Their T&C seem to be self contradictory. The eligible transaction excludes the air tickets transactions made in Mainland China by using the CUP cards while the promotion particularly includes the airlines transactions whether it's charged by a local or a foreign airline.

I just bought an air ticket on AirAsia and the transaction is made in CNY.
I called the hotline for clarifying this contradiction but all they could answer was that the transactions are classified as according to the merchant code and I will know if my airline transaction will be eligible for earning extra points or not once the transaction has been posted.