Hi Lee, PolyGram commonly pressed for both Australia and New Zealand at their factory in Wellington, and the precedent at 45cat is to enter releases under both countries if they were known to have been released in both (no doubt some were only available in one country or the other, and occasionally other Australian companies like CBS, EMI or Festival pressed for PolyGram, who didn't have an Australian factory). It gets a bit harder in the CD age where PolyGram's successor Universal uses "Australasia" in their boilerplate, but there may yet be separate Australian and NZ pressings. I suppose if in doubt, enter both (I can always check Platterlog for Oz releases 1988-2008), and then let someone tell us if something wasn't released in either country.
Discogs lists the country as Australasia as does the actual album. In the olden golden days the label would state the actual country of manufacture but the mid 80's this practice was replaced by the Australasia moniker which essentially means Australia and New Zealand. So I'll enter this album twice once for Australia and once for New Zealand. I don't think these albums qualify as International on the same same grounds that European releases are not considered international. It is more of a regional release like a European album but as a an Australasia category doesn't exist on 45Worlds (we have asked for years) a lot of mid to late 80's albums from this region will need to be entered for both countries.