I see… so if i’m reading this correctly you spend 10 hours +/- at each port. Given that you would want pretty quick access to wineries. There are some wineries in and around Hobart - i’m not really an expert on them but there has been some pretty compelling wine come out of Tassie. Here’s a link to the wine route: http://www.winetasmania.com.au/wine-route/southern-wine-route/winery-locations
There’s nothing too close to Dunedin, so do something else there.
The drive from Akaroa to the Waipara wineries is over 2 hours, so probably not that realistic. That said if you want to be aggressive about it Pyramid Valley and Bell Hill, just outside of Waipara are making special Pinot Noir.
The drive from Wellington to Martinborough is just over an hour, and a little hairy (scenic though!). Martinborough makes very good wine. I think the best choices are Dry River, Ata Rangi and Escarpment. Other good producers (and the 2 largest) are Martinborough Vineyards and Palliser.
Napier will be your no. 1 opportunity as there are plenty of wineries spread out in the Napier/Hastings area. The area excites most with it’s Syrah, Bordeaux Blends and Chardonnay, but they do a good job of a lot of different varieties. My pick of the wineries include Bilancia, Craggy Range, Stonecroft, Te Mata, Trinity Hill and Unison (all have great Syrahs, some have very good right bank blends). Clearview and Sacred Hill are also worth a look for their excellent chardonnays. Alluviale and Squawking Magpie are a pair of interesting newcomers… although i don’t know if they take visitors.
Nothing too close to Tauranga and it looks like you’re visiting Rotorua from there so probably won’t have the opportunity anyway.
For Auckland you could either do Waiheke Island (via ferry which leave right by where the cruise will be docked) or Kumeu in West Auckland. I’d probably do Waiheke given you’ll be at the docks. The wine quality has increased at a rapid place oN Waiheke with the picks (like Hawkes Bay) being Syrah, Bordeaux blends, Chardonnay and white rhone grapes. My picks are Man 'O War, Passage Rock, Obsidian, Stonyridge, Kennedy Point and Cable Bay. Cable Bay would be my pick for lunch. I’d probably just get a driver for Waiheke, although you can easily rent a car or get scooters. Waiheke is great, and you’re bound to love it, Although with only 1 day in Auckland i wonder if i would just explore the city and its neighbourhoods.
Waitangi is a no go for wine (or good wine anyway).