From the AA.com -

Complimentary upgrades are applicable for both the member and one travel
companion provided that both are traveling on a purchased, published fare
booked in Y or B, excluding fares beginning with YCA or YGT. Complimentary
upgrades are governed by the terms and conditions associated with the usage
of 500-mile electronic upgrades.
• Upgrades may be used on American Airlines or AmericanConnection marketed
and operated flights within and between the 50 United States, Canada,
Mexico, the Caribbean, The Bahamas, Bermuda and Central America.