Mr Key opened an Auckland version of the Big Picture Wine Adventure and Restaurant this week, accompanied by Big Picture founder Phil Parker.
Mr Parker and his wife, Cath, established the business in Cromwell about six years ago.
Although the Cromwell business is for sale, the idea behind it has been embraced by other wine-growing regions in the country.
Big Picture Wine Auckland, situated near the Auckland Fish Market, became the third of its kind in New Zealand, after Big Picture Wine Hawke's Bay opened its doors in October last year.
The Auckland business is co-owned by seafood company Sanford Ltd, believed to be New Zealand's oldest listed company.
Mr Parker said Sanford's investment was an encouraging endorsement of his business initiative.
"It's exciting to bring our business from Cromwell into the heart of Auckland city and to have the prime minister here recognising our effort and innovation. I hope he'll recognise Big Picture Wine as a contribution to New Zealand from our little southern corner," he said.
Marketed as an adventurous wine experience, Big Picture tours include aroma rooms, interactive films showcasing vineyards and wines, wine tasting, and food designed to match local wines.
The venture targets tourists eager to learn about wine industries in New Zealand's renowned grape-growing regions.
"The idea of opening in Auckland is to catch all those tourists that land in Auckland and never venture to our wine-making regions. It is all about inspiring them to venture deep into our wine-making regions and really taste New Zealand."