Surely a tax that explicitly names only foreign companies is the opposite of free trade?
Sure, China has driven a truck through the whole concept of the WTO over decades and so I doubt anything will happen. Free trade deals are very much toothless, on the assumption that they are supposed to make sense on their own terms so enforcement is not required. But I can see the USA especially if Trump wins a second term deciding that Australia should be trade sanctioned for discrimination against US businesses. The White House won't want to see tech firms become piggybanks for failed industries and economies around the world.