I don't believe that Yeomen currently require a clearance, but that might be changing soon. It's recommended that you be able to get at least a secret clearance. Without one you cannot issue ID cards and there are other limitations as well.
You are correct, Amber, YNs USED to require to be eligible up to a Secret (I believe), but a few years ago they took that requirement away. I have not heard if they were going to reinstate it or not. You don't need a secret clearance to issue ID cards. You just need to understand that the information contain in the RAPIDS program, is PII (personally identifable information) and protected under the Privacy Act of 1976, which most of our job is, and all of that information should be handled very carefully.