Are you fuckin retarded or something 1.5 B bounty is of WCI he didn't even exist in that arc. that's no bounty raise for him there.
dressrosa arc he got luffy got 500 mil and 0.6 of it is 300 or you can say 0.4 is 200M which got added to his 120M got him 320M.
eniess lobby luffy got 300M, 0.4 of it is 120,000,000 bounty which zoro got either way.
and zoro first bounty was 60M, 0.6 of 100m.
these are the occasion where both luffy and zoro got bounty raise. why you an absolute retard think someone will get a bounty if he was not in the arc in the first place.