To answer my own question.....
"For tickets purchased from 12 March 2006
From 26 March 2006, all passengers travelling in Economy or Premium Economy who have been ticketed after 12 March 2006 will be entitled to two pieces with a maximum of 23kg (50lbs) per piece. The allowance for Business Class will remain at a maximum of 32kg (70 lbs) per bag.
Additionally, from 26 March 2006, infants will be entitled to the same baggage allowance as the accompanying passenger, including car seats and strollers, but they will not be entitled to any additional allowances linked to the accompanying passengers frequent flyer tier status.
If connecting to or from a flight on United Airlines, Lufthansa or Air Canada, please note there is a maximum weight limit of 23kg (50lbs) per piece for Economy customers.
For all flights:
* Please note that if part of your itinerary involves travel under the piece system, then the piece system will apply to your whole Air New Zealand journey. If you are travelling on a Round the World or Four Corners fare, please check your ticket for the baggage allowance applicable to your journey.
* The absolute maximum weight per piece of baggage for all customers is 32kg (70 lbs)
* Each piece of baggage should not exceed total dimensions (length + width + height) of 158cm (62")"
Milliemoo
