I can say 100% that 60% of all bounty is a Scam. The reward for them is either given and the tokens will lie on your wallet forever or do not give at all. Then what's the point of doing this ?
60% of bounty is a Scam, 95% of ICOs is below ICO price. You should study and chose potential project to join. So you can avoid scam & low interest project. I found that several projects are so good (etc: MVP x2.25 ETH with a big bounty campaign)