Historically awards between the US and New Zealand has been one of the toughest things to book. Years ago Air New Zealand used to open up business class awards 60 days prior to flight. Then they stopped. There really hasn’t been meaningful Air New Zealand business class award space in years except for a brief span back in February.
Right now though there are a handful of dates over the summer where 2 business class awards are available using Star Alliance miles (e.g. United, Aeroplan, LifeMiles) between several U.S. cities and New Zealand on Air New Zealand.