So, it's an open source project. For any feature or change to make it into the code, it needs to be pushed to the git repo. Currently the people who can do that are me and @AudriusButkevicius.
For most contributors, that means someone else needs to "sign off" on the change for it to get merged. If you're considering a new feature, and all the existing committers say its a bad idea, then no amount of bounty will probably get it in there. Unless the bounty is large enough that you can effect significant bribes, I guess. But if a lot of people think it's a good idea, and someone is willing to implement it, there is probably something to it that we should not ignore... So I think it's self regulating. Not discussing it prior to silently coding in a basement for a month and presenting a code bomb would be a bad idea, though.
My process for promoting new committers is simple btw - if I've seen five-ten pull requests that are useful, nontrivial and can be pretty much merged directly without having to be extensively fixed first, you seem to be a great contributor and can be trusted to push code with your own judgement.
Anyway, if you're contributing something good, I don't really care if it's to scratch an itch, for the peace of mind, for the fame, to win a bet, or because someone paid you to do it. Hence, if people want bounties, by all means go for it.