Yeah, the Bundaberg range is definitely Australian. They do ginger beer (what Australians call root beer) as well as sarsaparilla. Both are fantastic drinks.
Edit: so if you're doing a search, you're probably likely to find it as "bundaberg ginger beer" - eg http://www.bundaberg.com/info/product_range/ginger_beer/
Bundaberg sarsaparilla is the same formulation as the root beer, not the ginger beer (http://www.bundaberg.com/info/product_range/sarsaparilla)
I have actually found a comparable Rootbeer in some common grocery stores that tastes almost exactly like my home made rootbeer, but not quite as strong. If any of you love _real_ rootbeer as much as I do, I urge you to try this!
http://www.amazon.com/Bundaberg-Root-Beer-4-pack/dp/B00HGGW6...
If you find it in a grocery store, STOCK UP! They are imported from Germany, and when they are out of stock, it seems to take about a month to re-stock.
Edit: Okay, I think the store clerk was either misinformed or lying to me, because "Bundaberg" is in Australia. Perhaps it is imported from Germany… and that is why it takes 1 month. But every store I find it at, seems to have only a couple left, and seems to take a long time before they "re-up."