If you are specifically interested in earning through bounties but fear that the project may turns out to be scam, then i would say that a legit project too can fail to raise a decent amount in a their ICO leaving nothing to bounty hunters. So, along with analyzing the legit project, one needs to look for the potential project before investing in an ICO or doing a bounty. I usually look for ICO ratings on various websites, telegram discussions, team background, project potential, social media presence and how reliable is the roadmap.