I don't think that bounties need to be a thing that is regulated by any organization.  It should be self regulated, and the market decides how it occurs.  If you want to only be paid in BTC or ETH then only take the bounty jobs that offer payment in BTC or ETH.  If you don't want a bounty job that just offers their token as payment, then don't take the bounty job.  Likewise if it looks like an iffy project, and you might not get paid soon or at all..... don't take the bounty job.  This goes back to the old saying...... DYOR.
I am sure you can contact these projects, and make them an offer if they don't accept then move on.
One last point to think about..... legitimate projects want their coins/tokens to be distributed..... to gain value..... Why would anybody else find value in a project, if the first person they hear about the project from, doesn't even want these coins/tokens?