You might be able to take 25kg with you on the plane. This is the reply I got from Air Tahiti a couple of weeks ago regarding on board lugguage:
The free baggage allowance on Air Tahiti flight is 10 KGS. For passenger holding an international ticket with an international arrival (and departure) within less than 7 days from first (and last) Air Tahiti flight, the free baggage allowance is 20 KGS on ATR flights. An additional baggage allowance of 5 KGS is allowed for passengers holding a valid international diving licence.
In addition to that, you can only get into the NZ lounge after check-in which opens AFAIK 2h prior to departure. If you're lucky there is an earlier NZ flight from PPT that night and you might be able to check in earlier. Otherwise the night at PPT airport is long and lonely...trust me
