It's convoluted, but if you click through enough times on AA.com, you will get to this page, which lists checked bag charges and what is waived for cobrand cardholders (though I don't think they've updated it recently to reflect the conversion of the USAirways cards to the AA Aviator products):
http://www.aa.com/i18n/travelInforma...ed-baggage.jsp
And then this page (which includes Canada with "Domestic"):
http://www.aa.com/i18n/travelInforma...efinitions.jsp