No, you're not allowed to leave.
Your nationality is irrelevant - while here, you are subject to the law of Australia, no matter who you are.
Leaving (or trying to leave) will be a breach of your bail conditons, and can be a separate, further offence.
In your case, even actually going to the airport (even groundside) could be a breach.
If (when) you are stopped at the airport (or dock, or wherever), trying to leave,
then you face arrest. You will then be put back before the court,where,
at the very, very least, you can expect your bail conditions to be varied
to include surrendering your passport.
At worst, you will be looking at the very real prospect of your bail being revoked
and going into full time custody until your court date.
Stay in Australia, and turn up to court.