Hi,
In the 'manage add-ons' section (after you log in) of myvodafone.com.au, check 'data bundles' and see if it says $0 min cost. Vodafone call centre people are not sure why it is $0. I think it is for postpaid. Zero dollar options for 6gb bundle as well.
Screenshots:
http://imgur.com/5k15thk
http://imgur.com/h1pL0Gg
No good here, for some reason I don't have data bundles on any of my services down the bottom like you do. The last thing on my page is Data to use in Premium Destinations