wineries - Marlborough sth island and up north around Nelson etc
Rotorua I have never been too but all told by kiwis and tourists it isn't that great.
Stick to one island you only have 12 days.
Auckland sucks - you may as well go to Sydney... it is just smaller and less interesting lol
Wellington is lovely but again you don't want to be spending too much time in a city like that - they are just cities like here but much smaller.... The best of NZ is outside the cities for sure.

Sorry for the dotpoints I am only phone still lol