Yes, AAA is offered and you can book directly thru Hard Rock. I recommend NOT going thru your AAA agent (no offense). My agent always tries to add in "extras" or "packages" which end up costing me a lot more than when I book my room myself.
For your information, the entertainment discount is quite a lot more than the AAA discount. I used my AAA discount for Disney WL and received 20% off my reservation. I used entertainment discount at Portofino and received 50% discount. But these discounts may depend on the season that you are going also. I'm going in off-season and called way ahead of time.
Good luck!