Australia is the seahorse breeding capital of the world so I would guess they are CB. They also have more species of syngnathids of any place as well.
Australia only has one seas horse farm these days and they don't breed subelongatus. There may be a few hobbiests who breed them but even then you will pretty much only ever see WC subelongatus in Australia and CB Kuda and Abdominalis (and even then that's only if you go through the farm, stores generally won't stuck them due to being cold water)