Yes, all in 2019 (which I know isn't recent, but I'm sure things have improved, not gotten worse)!
Marriott Melbourne
Sheraton Grand Mirage Gold Coast *
Sheraton Grand Hyde Park Sydney
* Hotel didn't know how to process gift cards. I left it with them when I checked out as well as my credit card number for the balance as I knew I'd be about $10 short. It took them about a week to process/zero out the gift card, and they never charged me for the extra $10.
The Westin Perth also didn't know how to process gift cards and I was running low on them anyhow, so I agreed to pay with my credit card as long as they waived the 3% credit card surcharge. They agreed.
2019 was shortly after the merger and there were many hotels (primarily from Starwood) that didn't know how to process gift cards. I have since used gift cards in Europe, middle East, Asia, Africa all with no issues.
I always recommend settling your bill the day before check out in case they have issues. Some times there's only one guy in the office who knows how to process them. The big advantages of paying with a gift is no foreign exchange fee (they are always within a fraction of the XE rate, sometimes higher, sometimes lower) and in Australia, you don't get charged the dreaded credit card surcharge. And of course, you get a 20% discount on your bill (and even more these days with the latest Amex offer of 33-40% discount).
Good luck.