Christchurch, without a doubt.
If the NRL want a team to help fill that 6pm AET Friday slot (easing the pressure on Sydney clubs who hate hosting it), then a modern, covered, rectangular stadium means crowd comfort on cold NZ winter nights, and the prospect of great playing conditions & entertaining footy for those TV audiences.
Add to that Christchurch has a successful sporting culture, and Auckland v Christchurch is the biggest sporting rivalry in NZ, then it's a slam dunk.
Wellington perhaps makes sense as the 3rd NZ NRL team - if that eventuates, but NOT the 2nd one.
And I say that as a proud Wellingtonian.
(May any fellow Welly folks here forgive me!)
On the actual areas themselves are they particularly growing in terms of the population. What about corporate support which is probably the only concern with a second NZ side?
Also whenever they do put in another side, let’s hope that the new side and the Warriors really push hard at RU; maybe even nab some reputable names