The world of "mifare" is a confusing mess. Basically there are RFID chips called Mifare "Classic" which have the chip model number MF1 IC S50 for their 1k chip, and MF1 IC S70 for their 4k chip. The memory structure and security feature set of these "classic" chips are unique within the ISO14443A family of RFID and NFC tags. These types of chips have been deployed for decades and millions of systems out there use them. They employ a proprietary security mechanism called Crypto1, which has been hacked and broken for a long time now. The xM1 used the S50 1k version, and the xM1+ is a "replica" version of this chip which has a built-in "back door" to allow direct manipulation of bytes in memory, including changing the UID (serial number) of the chip, which is not supported by the original "classic" chips.
There are also Mifare Ultralight, Mifare Ultralight C, and confusingly, Mifare "Classic" EV1 ... none of which are anything like the Mifare "Classic" 1k or 4k chips mentioned above in terms of memory structure or security features. In short, they are not directly compatible with each other, even though they all can "speak" with ISO14443A readers.
In Sydney, the transit system uses DESFire EV1, which is also ISO14443A, but is again nothing like any of the other chips mentioned above, including the Mifare "Classic" EV1. So, in short, you cannot copy a Sydney transit card to an xM1+, but take heart... We will have a solution for you later this summer!