Chain hotels seem to be pretty limited in NZ, though Club Accor has a pretty big presence. I'm currently 10 days into a 14 day trip, and so far have only found Hilton and IHG (ignoring Accor since it's harder to accrue points).

Otherwise:

1) Hilton Auckland - pretty basic, upgrade as a gold to a harbor room - breakfast was kind of meh.

2) Holiday Inn Rotorua - hotel was horrible, but expected for a HI. On the plus side, managed to stack 5 promotions, so for ~$90 a night we scored 12,000 points - not too shabby.

3) Intercontinental Wellington - really disappointed here. The wife is an Ambassador and that was barely recognized. Ignored our attempts at a better upgrade, and parking is $35 NZ a night.

4) Hilton Queenstown - awesome. Queenstown is amazingly beautiful, and we were upgraded to a relaxation room: bathtub/shower + fireplace + outdoor hottub + lakeside view. Definitely the best of the lot!

We ended up passing through Christchurch & Dunedin - neither of which seemed to have any good options. NZ is pretty limited in general - good luck!