For now a good bounty campaign is the campaign where there token already listed on an exchange so you will not worry whether you can earn or not. A good bounty campaign is the campaign wher there are already an exchange of the token to be listed. Try also to check of the bounty manager, for me bounty detective is good manager where lots of his campaign already has an exchange in the market.
But not every time there are bounty that has been listed in exchanges, Yes we are happy now because bountydetective as manager bring so many promissing bounty campaigns for hunters which already listed, but now i see almost all of champaigns managed by them want to closed, so we can't just rely on them