Is there any special trick to the flight centre gift cards? Ie can you use them elsewhere or is it more about getting a bonus in the flights?
This is only really worth doing when there is a special offer to purchase FC gcs at a discount. Personally unless it is 10% off (which is what they do 2 to 3 times a year) then the process is a bit laborious to earn the extra 'shop points'.
They can only be used at FC (AFAIK). You could ask about using them with Student Flights (owned by FC).
There is no point really as FC will 'beat' any airfare (by between $1 to $5 per person) as long as you have a screen shot of the prices and get them to book quickly before available seats at the price disappear.
The deal that comes up every so often with Coles and WoW is 10% off.
If you can access the 5% (or more occasionally) off Coles or WoW gcs then that offsets the roughly 5% 'activation' fee on FC gcs.
So using a suitable AMEX card you get points for the gc purchases, then you get points (Flybuys/used to be QFF on WoW, sniff, sniff) on the purchase of the FC gcs in store.
So adds up to a net 10% or so off your flights (cash cost wise) and you have all the various points gained from the 2 phase purchasing.
It does help to ring AMEX to confirm that you are still getting the free Travel Insurance (which they will generally transfer you to the insurance provider who will state that you need to be able to prove that you paid for 100% of the airfare cost using the AMEX card). You then ring back AMEX and ask them to add a note to your file that you spoke with XDCDX at insurance on March X, 2016 and he/she said as long as .... then you are covered.
Cannot be too careful or temp fate.
So you keep your invoice from the purchase of the shopping cards, and the receipt/dockets from the use of those cards (or e-cards) to purchase the FC gcs at a store.
... and that's all there is to it.
Once you become a serial offender then it is up to you whether you repeat the "yes you can do it" note added to your file or just rely on the first time.