It is really hard to detect scammed bounty campaign. After completing all the requirements to be able to get accepted in a bounty campaign, spending much time to participate in forums and not to mention carrying their banners, completing all the tasks and reports then all of a sudden you will just find out that you have been scammed already. luckily I am not the only one but to think all participants did the same efforts as well as you did. But it is really happening, lesson learned and could be just charge it to experience and move on. If we could only find out at early stage if we were in to scam or a legit bounty campaign. Who would really know anyway?
That's why you should filter tons of bounty campaigns and take part in dozens of them. Watch some managers, investigate the idea of chosen ICO and its team background. Check the quality of the website and WP, also check what is the stage of the crowdsale and how much they have already collected. You should gain experience and try different projects, then you will be able to choose wisely and take part in less campaigns.