New Prediction based on recent proceedings
Luffy - 4B or 5B
Zoro - 2.4B
Jinbei - 1.75
Dorry - 1.5B
Brogy - 1.5B
Bonney - 800M
Gorosei have now confirmed the existence and power of Nika. They either raise the bounty level and put it him next to Shanks 4.04B and BB 3.96 or put him out on his own at 5B. My guess is 4B because everybody knows of Egghead so the raise makes sense but they still want to hide Nika.
Mars witnessed Zoro defeating Lucci, an agent even a Gorosei praised, while still being clean enough. 2.4B would show he is the no2 that should be wiped out first even if Nika escapes or is to strong to capture, same way Queen and Lucci reasoned.
Jinbei as a former Shichibukai carries a big name in the OP world. His reputation is still bigger than Zoros. Mars witnessed him being there too. 1.75 puts him between Hancock and Crocodile.
If Mars thought Zoro and Jinbei took out Lucci together they could get modest raises close to each other again.
The rest of the SHP have not shown anything, flat raises or nothing.
Dorry and Brogy should sit fine around 1.5 each. Bonneys threat is high but is it higher than Robins? Not sure. 800 is still very high.
That's too much for Zoro. The only Yonkou's underlings I can see be over the 2 billions bar for now are Beckmann, Kuzan and maybe Shilliew.
Zoro just defeated a YC1 level dude. At most, that feat will raise Zoro's bounty to King level.
Same for Jinbei, that's too much. The other former Shichibukai have such high bounties because they represent a threat on their own :
- Hancock because she rules over a country full of haki users and has 3 forms of haki and a hax fruit.
- Crocodile because even though he's an "underling" of Buggy now, he has ties with the Underworld, has charisma and ressources to create several criminal organizations (Baroque Works, Cross Guild and mostly another one during the timeskip). And he has a powerful logia possibly awakened).
- Mihawk is sold as a more powerful foe than Shanks, a literal Emperor. And has a past of hunting marines.
In other words, those former Shichibukai can create mayhem if they will.
While Jinbei is a pretty peaceful guy who just follow Luffy's order. So at most, Jinbei will just have Queen's bounty level.
That's not enough for Dorry and Broggy.
Those dudes are the captains of the fearful Giant warriors pirates.
They represent a threat even superior to Hancock's. Moreover, they have ties with Nika and have knowledges about Nika.
A bounty of more or less 2 billions for those dudes fit them.
That's not enough for Bonney too.
Don't forget we have for instance fucking Smoothie who has same bounty than Robin.
So it's not crazy to think that Bonney might have a bounty superior to Robin's.
I mean, Bonney has Gear 3 level attacks with her "Nika alternate future" attack. And she controls every Pacifista looking like Kuma. That's some firepower in her hands.
At most, Bonney will have more than 1 billion.
For Luffy, I agree. He will have a bounty similar to Shanks and Teach.