The comments attributed to Oz Clarke regarding New Zealand’s increasing maturity (industry, if not vinewise) and that it is “entering into the next stage of its development in contemplating and legally recognising its terroirs” are very valid observations, but I do not think that the notion that the country is therefore shaping up to go down the full-on appellation route with associated detailed legal prescription and enforcement is quite what Mr Clarke meant. (See http://www.decanter.com/news/news.php?id=294045 ).
In common with other countries, and in response to the treaty-driven need for reciprocal geographical indication enforcement regimes, New Zealand is in the progressive process of creating its own structure of geographic names that may be represented on wine labels. Individual wine regions are going through the process of determining names and boundaries to apply to their areas. The existing list of approved names reflects the fact that some regions (such as Auckland, Waikato/Bay of Plenty and Canterbury) have made some at least initial decisions regarding their own sub-regions. Other regions are still in the pipeline, so to speak.
However, I am less sure that this was what Oz Clarke was really referring to. Certainly in many of the larger or more developed wine regions, especially Marlborough, Hawke’s Bay and Central Otago, there is a sense of increasing consensus regarding several vineyard sites or formations that are regarded as being a little more special than others. Certain vineyards “of distinction” are clearly evident, even though the New Zealand experience tends to be that superior sites are more often owned by winemakers rather than purely growers, so that the Burgundian and sometimes US experience of many wines being made from the one vineyard location are relatively rare. (The recent multi-releases of identified wines from the highly regarded Calvert Vineyard in Central Otago stands as one of a handful of notable exceptions; a number of top Gisborne growers also supply several wine companies with grapes of acknowledged quality, for example).
There is clearly interest in the regions mentioned and in other areas for ways to reflect the status of unique or superior grape growing sites. Whether this means going down the Gimblett Gravels route and creating a membership delimited organisation to provide de facto controls over production and labelling is not clear. The likelihood of adopting a sub-appellation form of delimitation based on a perceived or actual qualitative basis is less likely in egalitarian New Zealand, and probably best avoided.