Probably ISS, there was a visible pass over Sydney around that time so could possibly have passed over Auckland too. In my experience Tiangong 1 is faint enough that I wouldn't describe it as "very bright", plus it has solar arrays.
Use this Heavens-above link for all your Auckland based visible satellite passes:
http://www.heavens-above.com/?lat=-3...alt=13&tz=NZST
