Ok, I booked my Mom with Avios on AA, LGA-MIA, added her as an AU on my AA/Citi/Visa Signature/ Platinum card last week, they overnighted the card free of charge. As she arrived to the airport they didn't wanna honor the free bags at curb-side check-in, she demanded a supervisor, the agent went inside to consult, he came back, escorted her to an inside counter where she was honored a free bag for her and her companion. Again, 1 free bag for each passenger!
Although I was told by the Citi agent (when ordering that additional card)that an AU -and up to 4 passengers on the same reservation - will be waived for 1 bag, I didn't wanna post it until she was proven right.
There goes all the speculations..