Is the 1mb per day free data on the Australian SIM Card for use in Oz and is the out of bundle data £0.03 per mb?

Not sure I understand the question you have raised but the SIM will faciliate data. It would be best to contact Lebara on arrival and ask for a data top up or to buy a data top up from a local store. This will provide bigger data packages for use in Australia and therefore enable more flexible usage.