If your income is too high for either of these you may still be able to get a health-care card which doesn't pay an allowance directly but still entitles you to the same concessions. If you're on one of these benefits there are a bunch of other subsidies you're probably also eligible for and, being a government organization at heart, Centrelink are extremely unlikely to tell you this. I only found out through repeated questioning and searching the Centrelink website. If you suspect you may qualify I suggest phoning Centrelink and asking them directly. If you are in receipt of one of those government benefits you will receive a health-care card or pension card.
Many organizations provide discounts to card holders.
You are also allowed to travel on public transport using concession tickets. Many other places have concession rates if you ask but may not advertise the fact. It's always worth waving your health-care or pension card around when you are about to pay, and asking if there's a discount. If you happen to be well enough to travel but not well enough to go by yourself, both Ansett and Qantas offer discounts to disabled people travelling with a carer. You'll need some sort of documentation, probably a doctor's letter, and you should speak to the airline well in advance of booking your flight.