Yes, it is very much necessary thing to choose a right bounty program for participating. Otherwise you will not get enough reward for your efforts. It had happened with me in the past like before I am selling my rewards that coin was dumped in the exchange.
Some members of the Bounty are guided by the name of the Bounty manager of the company, others study the information about the projects, and the third simply pays attention to the general Bounty Pool of the company. I believe that you can not separately consider all these points, because only together they can characterize this or that ico company.