Should be no problem checking through from AKL.

9 Hours is a long time but QF F is far from the worst lounge to spend 9 hours. The food is excellent with the four course dinner.

I realise you have been to sydney a lot but i think compared to a few hours in the IBIS, i'd plump for the City Circle train into circular quay and have a walk around the Botanical Gardens or go to Central station and walk to Darling Harbour and treat yourself to the Sea Bugs in Nick's at darling harbour. Much better than the IBIS!!