So, credit card churning has been stomped out by a lot of banks in the States but I'm trying to figure out who still allows it in Australia
By churning I am assuming you actually mean gaining a card for points and then cancelling and repeating endlessly???
In Australia to best of my knowledge this has never been able to be done on the scale you could do it in the USA where one could for example just keep churning a Citibank card several times a year for years on end (now ceased)..
So the answer to your question if you mean this , is no-one as it was never was.
It has been possible to churn to some extent, but at a much greater gap between renewals.
ie I have had a number of cards over the years that I have had before. however bonus joining offers are sometimes conditional on not having had that card at all prior.
Luckily the various card suppliers have a variety of cards come and go, and so most years I gain some attractive sign-on offers. Some cards are not worth it due to the sign-on fees. Amex has been goo of late as one can grab cards with flights worth more than the fees, with sign-on bonuses on top of this.
This last 6 months has meant I have gained for me 75 K Amex MR, 40 K of Citibank and for my wife 80K MR and 100k Citibank.
Gone it seems are the days where you got points and had the first year fee waived. A number of years back I got a Qantas Amex with 35K sign on points with no card fee for my wife and I, and then repeated in 3 months laters when the same offer came out. Initially they knocked me back on the extra 35K, but when I asked them to show where in the T&C it was precluded, and they could not they then coffed up the points. So 140 k in 3 months for $0 cost.