Well unlike all the other examples you quote Richard, Shiraz is not a
geographical name from Australia. The word could be said to have a
Persian clang, Shiraz being a large city in ancient Persia/ today's
Iran.

Lore has it that the grape was brought by returning crusaders from the
Orient to the Rh=F4ne valley, where it took the spelling of Syrah, being
not too far from a francophilic pronunciation of the Persian Shiraz
(the i in Persian being pronounced more as an e would be in the
European languages and the y in French not at all like "my" or "thy" in
English). This is most likely false, but makes for a nice story.
Certain documentation suggests that it was brought to Australia from
France in the 19th century under the spelling Scyras, which became
Shiraz either as an articulative simplification or due to the romantic
era infatuation with the Orient.

I have seen, bought, tasted Shiraz at various occassions from South
African (never had a chance to taste a truly impressive one
unfortunately) and even from Chile and the US quite naturally, without
wondering why they have chosen the name Shiraz and not Syrah. But
coming to think of it, this may just be an attempt to position
themselves distinctly from European products, or just to piggyback on
the reputation built by the Australians.

Cheers