Here is a simple answer:
It really depends on what that particular gym/fitness manager/owner is looking for in a trainer. The vast majority of locations prefer to hire certified trainers. Beyond that, adding a college degree and experience are also in the qualities they are looking for in trainers and would definitely help with the hiring. I can’t tell you how many times I have witnessed trainers with only a certification in their arsenal who had no idea of how to train clients. They copied other more experience trainers and then pass it on to their clients. Others had more experience even without any college degree to back up their knowledge. And then there are those trainers who do have the college degree and a certification, but no experience.
So the question here is what are you looking for when hiring a trainer? Personally I would look first the type of certification they have, then if they carry a liability insurance (especially if they are going to be hired as independent contractors), experience and then a degree. Today, the best trainers out there have a graduate degree in exercise/sports science or exercise physiology, one or more certifications and most importantly many years of experience.
But like I said, it depends on the gym which you or anyone else is looking to get hired at. I hope this helps.