As some of you are aware, I have designed the electronics for the e-payment platform for City of Cape Town.
As an experiment, I physically made an RFID tag, and yes, it works:


The item above, will work as it stands, on the City of Joburg's METROBUS, the only obvious issue is that when fares are loaded, they will probably give you a really hard time at the paypoint and regard you with suspicion.