You need to make research to know whether a bounty manager is legit or not, but I can say that a newbie bounty manager will still be legit just look at the project and also join their bounty telegram group and see how the bounty manager responds to the participants.
Have you been watching all of the scam projects that happened since the first quarter of this year? the majority of the scam projects have been running by the newbie campaign manager and i can mention some like swaphub and various scam defi projects. Their project didn't guarantee if that will be a legit project or not. As far as i can see that depends on whether the project already traded or not. Even some legit projects can refuse to pay the hunters.