No reply from the club but I found this in the Q and A's
Details
Etihad discounts are only available for selected flights. When a discount for a selected flight route is made available we will email you with a discount code for that specific flight.
Cityzens Membership is sold subject to availability and issued subject to Manchester City Football Club’s 2014/15 season Cityzens Membership
Terms and Conditions of Sale and
Ground Regulations.
Call the Supporter Services team on 0161 444 1894 (option 1, 3) if you have any further questions. You can also follow us and ask any questions via our official Supporter Services Twitter account,
@MCFCHELP.
We are open Monday to Saturday 9am to 5:30pm. Closed Sunday and Bank Holidays.
So not very easy to claim it then!!!!!