There are two companies I know of and have used to pay everyday bills using bitcoin in Australia. Effectively they take the bitcoin, convert it to Aussie dollars and pay your bill.

The longest running one - since about 2014 I think - is the Living Room of Satoshi (https://www.livingroomofsatoshi.com/) - and one thing I really like about this site is their statistics section. You can see who is paying for what (aggregated not identifying) - unsurprisingly credit cards and tax payments are usually the biggies. Supports a bunch of alts which I guess is a good way to ditch any you've got left.

Another one is PayBTC which has been around about 5 years now (https://paybtc.com.au/bpay) - same concept but slightly more limited scope - focuses on any bill that can be paid using BPay with a BPay code and reference. Love the simplicity of this UX and the fact that it's bitcoin-only.

The only other equivalent service that I know of is Bylls run by Bull Bitcoin in Canada - I think they started around the same time as Living Room of Satoshi - and let's face it - running a bitcoin business for a decade is a damn solid track record!

Both these Aussie businesses are run by reputable long-time bitcoiners in Queensland (God's Own Country) and give lots of flexibility to Australians about how you can use your bitcoin.