Bounties today like faucets 5 years ago, it is very difficult to find good bounties even those managed by top managers with good reputation do not guarantee that the bounties they manage can be successful, in my opinion this is because of the difficulty of the project for the collection of money, so many fail .
Participating in bonus campaigns managed by top managers will reduce your risk somewhat because they did the research before accepting that project manager. The bounty manager is not directly involved in the development of the project so cannot give you any guarantees. The success of a project depends on the project team and has nothing to do with the bounty managers.