To be tagged as Halal it has to be slaughtered a very spacific way. And if you ask they should be able to provide the certificate for you varifying the how, who, when and where for the Halal certification.
I too am very shocked you were able to get it at such a low price. It's not the highest grade of Wagyu, but still......
The high level answer about the Australian part. Many years ago a Japanese cattle rancher and an Australian cattle rancher did some business and the Wagyu/Kobe breed was cross breed with cattle in Australia. My understanding is as long as it is more than 50% Wagyu they can sell it that way. It is no where the same as the Japanese Wagyu, and they don't export the highest grade out of Japan. So we get the lower grades in the States, but it is still very good.