I've actually created a thread of my own issues with my bonus items in DA 2, and they are explained better in it:
http://social.biowar...581922#6581922 - but here is the short version.
I have indeed entered my codes here on social.bioware, all account information between here, my 360 gamertag, and my email are all proper and match. The bonus items show up here in my content, but in neither my unlockables nor in the Special Deliveries Chest in Gamlen's house. Just to make sure that all of my information is correct, I checked all of my DLC items and bonus content for my Mass Effect 2 game, and they all work perfectly.
I've contacted EA a few times, and from what the agents there have been telling me (and what I can see for myself by looking here) - all my entitlements show up on this account. Across both games, but only one of them is working as intended. If anyone can help me sort this out, as EA has done their best but apparently has a wrench in the system somewhere, I would appreciate it immensely!