Ok, I think I know where the confusion is coming in, and I will confirm tomorrow.
The Ticketek site states
"Club Members and General Public Reserve - 16 tickets per transaction (8 tickets per transaction to Anzac day only)"
I suspect this means you can get 8 tickets in one transaction with 8 member barcodes, not that you can get 8 seats for every barcode.
Reading between the lines still though, and I will get it confirmed first thing tomorrow.
Hope you find a spare flexi 6 game membership - but it may be worth buying a kids one ($65) for the seat...