I took the organ stealing much like Blackbeard's delivery of Ace to obtain the power. So I was assuming he did some major owning in the NW or in Paradise to jump up the 240m because they said he sent them "in order to become" so I doubt they go yes MASSIVE increase in bounty and now we freeze it and make you a Shichibukai….
One doesn't rule out the other. I mean let's say that he cleaned up in the NW world, he completely destroys a couple of high profile 100 million new world pirate crews. Let's say 5-6 of 'em over time. And after each they punch up his bounty accordingly. And then afterwards he reveals that it was all just one huge publicity stunt. And voila he's in big bounty and all.