Here's the breakdown if you decide to credit to QF.

AKL-HKG-AMS-HKG-AKL in J will give you 560 Status Credits (SCs) if you credit them to the Qantas FF program. You need 700 SCs in your membership year to attain Gold/Sapphire. Thereafter, you need 600 SCs to maintain Gold.

Depending on how many other OW flights you have credited to your account in your current membership year will determine whether or not you will be able to reach Gold.

The critical thing to note is that you MUST fly a minimum of 4 QF sectors within your membership year in order to attain Gold. Living in NZ certainly helps as you have plenty of opportunities for relatively cheap SC runs on QF services. QF strictly enforces this qualification rule – a colleague of mine based in the UK has recently clocked up 1,100 SCs on BA and IB, but as she has not flown a single QF sector in her membership year, she remains a lowly Bronze

Hope this helps.