I wonder where the OP looked on aa.com? Under Admirals Club Admit Policies it clearly states:

Access Based on Class of Service
First Class# (see exception)
#American Airlines passengers must be departing on an international flight. International is defined as Europe, Asia, Central and South America, and Mexico City. Excludes American Airlines passengers traveling on solely North American itineraries. North America is defined as U.S. (including Hawaii and Alaska), Canada, Mexico (except Mexico City), Bermuda, The Bahamas, and the Caribbean.

And the info is also right here on FT in our wiki:
http://flyertalk.com/wiki/index.php/...#Admirals_Club

I absolutely do not understand why the wiki is so under-used. It is a fabulous resource, that is readily available to answer 99.9% of the most frequently asked questions.