You have to book the entire package through AAA, including room, dining,and park tickets.
The same thing happened to us when we initially tried to book our package through AAA--the price came back exactly the same as Disney had quoted us with no discount. We questioned the AAA agent, and she called us back the next day and apologized, and said they had made a mistake, and requoted the correct price. (She also said four other families had made the package reservations, and she was going call them back and give them the good news--we were glad we saved someone else a few bucks too!).
Most of these AAA agents do not know NEARLY as much about Disney as the folks on this board, and you shouldn't hesitate to grille them if something doesn't sound right! Once you manage to get it done though, I think the AAA package with dining is a good deal!