just gotta find where the antenna is mentioned
If the contract says 'x' antenna points, than all you'll probably get is 'x' points.
If it says wired points, then you'll get that.
If it says antenna wired to 'x' points, then you're good.
Digital tv transmission ranges from approx channel 9 & 10, up to around sbs/channel 28 & 31. Allthough thats in melb anyway, i don't think other states are much different.
So if you can get those channels ok, digital will be fine.