I had problems, in the UK, sourcing V Rated BT46s. I contacted Bridgestone and their guy, Gary Hartshorne, came straight back to me and could not have been more helpful. Found me a stockist who, incidentally, had told me they hadn't received any in the size I wanted, and I received the tyre two days later.
So, I would recommend contacting Bridgestone Oz and hope you get service as good as I got.
I doubt that Bridgestone Australia would be helpful to individual buyers.
I was also after some V rated BT46 tyres a while back and couldn't find any in Tasmania. I rang Bridgestone Aus and they told me to contact my local tyre supplier. When I told him I couldn't find a Bridgestone tyre supplier in my state, he said he couldn't help me.
My local bike mechanic/parts shop that's usually my first port of call if I need stuff like tyres, brake pads, etc. is Red's Motorcycle Repairs in Tassie
https://www.redsmotorcyclerepairs.com.au/.
Not to be confused with forum member Red (Redax) in Brisbane. Tassie Red is the only motorcycle mechanic in Tasmania that I trust. There are some cowboy mechanics around that I wouldn't let anywhere near my bikes, but that's another story.
Red explained that he couldn't get Bridgestone tyres because Bridgestone Australia wouldn't do small orders. Red's shop is a small one-man business, so it's only economically viable for him to buy in small quantities of tyres at a time. Bridgestone would only do business if he ordered a container load of tyres, to be paid for up front. There was no way his business could finance a tyre order of half a million bucks.
Red has some kind of dealer arrangement with Dunlop tyres, but he can get any other brand of tyre you want, as long as it isn't Bridgestone. The last tyre I bought from him was an Avon.
Even the larger motorcycle shops in Tassie can't justify orders of that quantity, so Bridgestone tyres of any sort are a pretty much unobtainable in Tasmania. The only way I could get what I wanted was to buy from one of the large tyre outlets on mainland Australia and pay the freight to Tassie. Forum member Levo was helpful because he used to work for a motorcycle tyre business in Brisbane and he put me onto someone who could send me what I needed at a very reasonable price.