From Barclays site:
How do you define travel?
A travel purchase and redemption is defined as: Airlines, Travel Agencies & Tour Operators, Hotels, Motels & Resorts, Cruise Lines, Passenger Railways and Car Rental Agencies as defined by the merchant category code. Purchases made at merchants that do not process transactions under these terms or that use incorrect MasterCard merchant category codes will not qualify. Barclaycard is not responsible for incorrectly coded purchases.
I suggest booking a flight for a friend and having them pay you back and having Barclays reimburse you too.