I'm a Melbournite, a 1000km south of Sydney , but I've known of the phrase since I was very young.
An example would be if you were at the horse races, losing heavily,
with just one race to go. Turning to your mates you would say, "I'm
betting the last of my money on this one so, depending on the outcome, its going to be Sydney or the bush for me."

JG / FME