As long as you have active autopay you will receive the autopay reward as described here. I had an issue where my account was not reporting the credit. To fix this I removed my autopay information an added it again.
It's my understanding that once you switch to a rewards elligble plan you'll receive loyalty rewards for your time with Public Mobile since May 2014 (after the account was activated on the 4G LTE network). For more information about that you can read this post.
Hopefully that clears up all your questions!