I've seen lots of fans complaining about why the bounties of sanji's gang went up. Bounties don't increase just because the rest of the crew's bounties increased. Remember when nobody except zoro and luffy's went up? Sanji's team might have ran into some marine trouble for all we know. I mean at first we thought they were going up against big mum, next thing we saw capone was intervening, then again with kaido's crew. Clearly we don't know what happened to them during dressrosa. Who's to say the marines wasn't involved. All I'm saying is that something went down and the marines must have known that's why nami, chopper, brook and sanji got new bounties too 