I recommend skipping Wellington and going to Napier instead, especially if you're interested in wine and good food. We spent four days there in March and really enjoyed the area. Large wineries (Craggy Range) with decent wine and small wineries with exceptional wines (Black Barn). Both wineries also have excellent restaurants. And Napier is a neat little city with art deco architecture. We stayed at the Pebble Beach Hotel, which was very comfortable and right across the street from the ocean.
Our other wine stop was Blenheim where we spent three days exploring wineries and playing golf. Beautiful valley filled with good wine. We stayed in the Springvale Cottage at the St. Clair Winery. The two bedroom cottage was very comfortable with a well equipped kitchen and an outside grill.
We also enjoyed Kaikoura. The peninsula hike was spectacular and not too hard on the knees. There's only one winery there but its worth a visit just to see the view out over the ocean. We spent three nights at the Kaikoura Cottage Motel. Each of the two bedroom cottages have kitchens and comfortable living areas. The owners, who built the cottages and hard working and justly proud of their business.
Have a great trip! I can't wait to visit New Zealand again.