@TheCrystalShip:
LOL, it would be funny if she were just a bratty kid who ate the DF, and used it to appear older so she could become a pirate.
Maybe the WG wants her back, because she is the young daughter of a noble?
I have read an interesting theory about Bonney being the daughter of one of the Yonkou, specially either Kaidou or Big Mum, it belongs to LordRayleigh of Mangahelpers:
! @Lord:
! > THE WORLD GOVERNMENT CONNECTION
Jewerly Bonney was a pirate rookie 2 years ago who reached Sabaody Archipelago as one of the Supernova. After the war, we learnt that she had escaped from the World Government and that it really had scared Admiral Akainu who was glad she came back under their control.
Why Akainu was personally scared ? We know that Akainu was a Marine Admiral at that time and wanted to become the next Fleet Admiral - this was later proven by his 10 days fight against Aokiji on Punk Hazard. We know he had planned to transfer Marine Headquarters from Marineford to New World and since then he has been growing the Marine's strenght in order to prepare it for some big clash - Law's words.
So my guess is that Sakazuki was scared the disappearance of Jewerly Bonney could have threatened his big scheme by preventing him to transfer the MHQ. I think that Akainu wants to deal once for all with the New World pirates and the transfer of the MHQ was the first step of his plan. Remember he believes in absolute justice as showed in the Ohana's destruction and the Marineford war.
That's why the Admiral was personnaly scared by the event and went himself to take Jewerly Bonney back after the Blackbeard Pirates tried to exchange her against a marine battleship. I don't think that Akainu would be scared by anything except his unability to deal with the pirates with his absolute justice. That the world government officials change is none of his business, his role and leitmotiv is to kill pirates.
So I think that Jewerly Bonney has ties with powerful people and is actually being taken hostage to protect the Marine/WG from a conflict against them. She told Akainu she will never forgive the World Government because since her childhood she has been taken as an hostage and had no freedom. Her words just reflected her personal relationship with the WG.
THE YONKO CONNECTION
As far as we know, there are only two kinds of people who are enemies to the WG, the pirates and the revolutionaries, and among the pirates the real dangerous ones are the Yonko. So these are the two groups who can threaten the WG.
I don't think she is an hostage against the RA because they are active and fighting against the World Government. Dragon is Luffy's father and they already had Ivankov and Inazuma but couldn't do anything to stop the revolutionaries. So the RA would not be affected by the hostage.
What about the Yonko ?
- Blackbeard captured Bonney and was a nobody before the beginning of One Piece's story, so he's out.
- Shanks has a good relationship with Sengoku and Marine and has fun in New World.
- Whitebeard had a personal story with Bonney but he died and Akainu was still concerned about Bonney - my bet is that Whitebeard could have helped her escape.
- Kaido seems like an evil guy who is building his smile army in the shadow, so he is a candidate.
- Big Mom is a crazy Yonko with an unstable mind as showed when she turned berserk for candies and how her crewmates are scared about her reactions, so she is a candidate
We don't know much about Kaido and Big Mom, so they could both be the one. Kaido could have been building his army in secret - as Law said - because of that hostage. And Big Mom could have been blocked into New World because of that hostage. I'm sure that her madness could have led her to take control of the "Gourmet City" Pucci which is in Paradise (it is connected to Water 7 through the Sea Train). She isn't the one you can reason with as shown with Baron Tamago about the treasure.
JEWERLY BONNEY AND BIG MOM
Despite the fact that Big Mom's name is Charlotte Linlin, I think Jewerly Bonney could be linked to Big Mom - the child normally takes the dad's name. The fact she doesn't have any manners could come from a pirate family.
First, Big Mom and Bonney both eat a lot. We didn't know about Big Mom until Fishman Island and the candies, and Bonney has always been showed as a big eater - when Oda was asked to draw the supernovas in their childhood, Bonney was drawn eating.
So both were first introduced as gluttonous people.
!
! @Lord:
! > >!
! > Secondly, Big Mom and Jewerly Bonney have the exact same hair colour. They both have pink hair.
!
! >!
! Thirdly, the Bonney Pirates ship looks like Big Mom's headquarters. Bonney's ship is a cake just like Big Mom's main island.
! >!
! >!
! So do you think Jewerly Bonney could be Big Mom's daughter ? Akainu was scared because they had lost control over Big Mom's daughter, and he thought it could lead to a war with the Yonko. Plus, since the Yonko is in the New World, he thought the Marine would lose their historical chance to transfer their headquarters into the New World, which is a strategic move to get rid of the pirates once they will be stronger (the government has given the Marine better means).
! Bonney being an hostage was/is the only way the government found to make sure this Yonko who is a total berserk doesn't turn wild and crazy and attack any island with delicious food. Just as she doesn't care about the Yonko management - treasure and boats - she doesn't care about world balance. What matters is only her candies.