Dunedin We did a HAL ships tour on the Taeri Gorge railway. The train left from the ship and it was a really good day. Yes it was expensive but we were given lots of food and drinks and the staff on the train were fabulous. The scenery was pretty good. the people that booked on their own had to get the bus into Dunedin to join the train.
Wellington Get the shuttle into town, the National museum was really good. then the cable car to the top. ( can't remember the name ) We had a lovely lunch at the top then walked back to the shuttle through the botanic gardens. We were mid february and the gardens were really beautiful
Melbourne,, I think going to Phillip Island to see the penguins come ashore would be my definite. Maybe on the 2nd visit as it will be a late night.
Tauranga We did a ships tour to Rotorua and it was a very interesting day