Huhu,
Anscheinend kannst Du bis zu 4,5 Liter importieren:
Zollbestimmungen:
Zollfrei nach Neuseeland dürfen folgende Waren (zusätzlich zu den Dingen des persönlichen Bedarfs) eingeführt werden: 200 Zigaretten oder 250 g. Tabak oder 50 Zigarren; 4,5 Liter Wein oder Bier und eine Flasche Spirituosen bis 1,25 Liter, weitere Artikel im Wert bis zu NZ$ 500,.-.
http://www.yellow-effects.de/reisefuehrer/Land/neuse…
und, noch besser und sicherer:
Cigarettes, Cigars, Tobacco, and Alcoholic Beverages
In addition to the $700 duty free goods allowance, all passengers 17 years of age and over are entitled to import the following goods free of duty and exempt GST.
Cigarettes, Cigars, Tobacco
200 cigarettes or 250 grams of tobacco or 50 cigars or a mixture of all three weighing not more than 250 grams.
Alcoholic Beverages
4.5 litres of wine or 4.5 litres of beer—this is equivalent to six 750ml bottles
one bottle containing not more than 1125ml of spirits, liqueur, or other spirituous beverages.
Note: The minimum age of eligibility for the above allowances is 17 years. This is the age limit prescribed in international tourism treaties to which New Zealand is a contracting party. The Sale of Liquor Act 1989 and the Smoke-free Environments Act 1990 prohibit the sale of alcoholic beverages and tobacco products to persons under the age of 18. This restriction also applies to New Zealand duty free outlets.
Full Customs charges are payable on goods that are not eligible for concessionary entry, e.g., bottles of spirits, liqueur, or other spirituous beverages in sizes greater than 1125ml or are in excess of the allowances listed. No revenue collection will be made if the amount due is less than $50. This waiver does not, however, apply to tobacco product.
direkt vom Neuseeländischen Zoll: http://www.customs.govt.nz/TRAVHOME/advice1.htm#18
War wohl nix mit selber saufen 
Bye
Rolf