I haven't flown domestic from Wellington since last year, when I did it a few times, and I don't recall ever going through anything resembling security (except checked bags). I recall someone talking about upcoming changes, do they do security checks/bag scanning for domestic now?
The three cities that I fly though a lot ( Auckland, Wellington, Christchurch) always have full screening to each other. No screening flying to regional airports though.
So after traveling this week, yes I had to take out the laptop leaving Auckland, but leaving Christchurch they wanted laptops in your bag and had signs up to that effect.