Surely Alliance, now that they have at least 1 F50 based in NZL, could start Alliance NZ & put more F50's onto a NZL AOC. Don't think extra F50's would ever need to even go to NZL, but could fly around in OZ, without restriction or any reference to CASA.
If the NZL side of the business grew, they could also put F70's/F100's on their NZL AOC.
It appears that NZL tourism believes they will be getting millions of chinese flying around NZL spending billions soon, so perhaps Alliance could get a piece of that pie, even if they operated under an NZ flight number.
Alliance are close to VA(recent FIFO announcement) & NZ owns a good chunk of VA & surely Alliance costs are much lower than NZ's, so why could Alliance operate some of NZ's thin routes, especially now as JQ Dash 8-300's are taking some of NZ regional business.
Alliance could fly F50/F70/F100's around NZL in NZ colours, just like they do for VA/QF in OZ sometimes. Must be plenty of routes in NZL that can't justify a B733(are there any left?)/A320.