I don't think there is a way to be sure an ICO or bounty program is legit. Do the work and hope to get paid is what it looks like to me.at Einvion there are thousands of people waiting for your token. You're not alone.
There are a lot of ways to distinguish scam from a normal campaign. For example, publicity of the team, famous advisors, experience of the admin conducting bounty campaign, statistics on the rating platforms, activity of the campaign at public events, and many more.
if you are very observant, then you'll be able to recognize scams. My personal statistics is that 1 campagn out of 100 is scam.