In these cases I usually 1st clear it with whomever before I go and buy anything to 1st make sure they will reimburse me and to what amount. I also ask that they make a note on my PNR about it in case it hits the fan afterwards.

On a recent Outbound Intl flight my connecting carrier left 1 of bags behind (as well as several dz from others also connecting from other carriers), I asked and they checked and said the bag was at XXX (connecting airport) and will be on the night flight and thusly anything I purchase will be on my dime. Thats why I always ask before assuming I will be reimbursed

If you arent getting love from AA did the CC used to purchase the tkt have benefits that kick in under flight ins or whatever they call it, a number of CCs have this