I am concerned that some forumites still seem to be confused about duty free alcohol under the new regs. Please be assured you can still take bottles of booze (1 Litre) on board in hand luggage if you pick up your duty free after you pass through customs/security. Most duty free shops will send to airport for you to pick up after passing through these parts or you can buy at the shops in the airport.
Hope this helps. See below.
24. Can I still buy Duty Free when I travel?
Australian airports
Yes. In Australia, you can collect or purchase duty free once you have passed through international screening for your international flight. At Darwin and Adelaide, domestic and international passengers are screened through the same screening point. These airports will have a separate international screening area for international flights AFTER the first screening point.