Updating my own thread in case someone searches for this in the future.
On January 4th, a TG rep in Australia told me the answer was no. i.e. For a ROP *A award on NZ, the domestic flight would have to be with "Air New Zealand Link" rather than "Air New Zealand" and the former is not in the *A.
On January 5th, a TG rep in New Zealand told me the answer was yes, and successfully booked the award tickets accordingly; NSN-AKL-BNE-CHC-NSN being the bext option available. The only theoretical proviso was no stopovers, but in saying that she had quoted one version of a route that required one - last evening flight NSN-AKL, first morning flight AKL-BNE.
The moral? Keep asking until someone gets you what you want?