this is a theory i just came up with i'm pretty sure about. here's my train of thought.
bounties cannot be given for events of which there are no witnesses. for sanji this means jabs and wanze. for zoro it means no t-bone or kaku, etc, etc. which means we've basically reached a point in the series where bounties will lag an arc.
now if we look at the actions of EL, i think it's pretty evident that the bounties will get a real hiking in regards to the main characters very soon. i would even say the next time they run into the WG.
i believe that for the moment luffy's bounty is about right from our point of view but will be quickly hiked up once the WG place all the pieces together, i.e. all of CP9 defeated by his fighters, he holds the keys to resurrecting the weapons and he holds one of the worlds best shipwrights as a key to actually making the weapon. at this point the only thing we know is that franky is the most technologically advanced thing/up there in the grandline. once the power of the mugiwara is realised, they're sure to dwarf a lot of pirates' bounties.
if you take into consideration all of that, there's no way luffy's bounty is inclusive of his fight with lucci, unless of course the powers that be, like me believe he's a mid-tier fighter at best. which means the bounties were issued on actions based around the initial invasion upto entering the tower and before.
that without a doubt means that the bounties are about right. chopper hasn't done anything to warrant even being though of as anything other than a pet yet and usopp has his sniping ability on the tower, plus his exploits on the sea train being valued at 30m berri. where that leaves him in regards to really being the king of the snipers is imo a long way. but we have very little information.
if you look at sanji and zoro for example, sanji has his role in arabasta and also his role on the sea train, not forgetting his role in the invasion of EL and zoro would have had his prior acts plus the slicing of the sea train and the showcasing the ability to chop the wooden door. his bounty makes sense. then even if you look at nami's, 16m for taking out so many marines straight off the train, that's about right too. and as for franky's, i believe that he's somehow managed to receive his bounty for the work of the battle franky's along with him trying to stop the initial sea train.
so in short, i believe that the actions of the Judiciary Tower will not catch up to them before the finale of their next arc or even the finale of the next major arc.