I was on that flight earlier this week. We received a small bottle of water and small snack - definitely nothing replacing a meal. I would make sure to bring enough food, while there are options in the terminal in Sydney the wait can be long after a flight has arrived and everyone is waiting for the same connection.

As mentioned no WiFi or entertainment, also keep in mind that any bags will have to be picked up landside in the domestic terminal in SYD and re-checked at the international terminal.