Looks like you simply gave a favour to privately owned wine importers who's shares you couldn't buy?
It's reasonable to assume that these folks may have significantly reduced NZ's imports of SA wine for at least a while.
The conservative govt that had encouraged the whole Springbok tour in 81 also was the same govt that so mismanaged the economy that it fell apart in 84, they were replaced by a left wing govt that brought in free trade and scrapped all these licensed etc (not the usual left/right narrative)