Hey! I did classics in 2012 and it is far the best subject of the VCE! What texts are you doing?
From my experience, the work load with classics was quite a pain in the ass, and I was only in year 11 so it was quite easy for me to drop all my other subjects and focus on it! I couldn't imagine doing it in Year 12!
I did both Latin and Literature as well as classics throughout VCE and they definitely do help! In classics essays when it comes to discussing socio-historic context, your ancient culture knowledge that comes from Latin will surely help you out there, and for literature (if you are a good writer), you should have no problem.
I got an A+ on the exam, and the best tip I can give you is: know your texts really well (especially your comparison texts), and when you have to do your two short answers, make sure you kept your answers really precise, make a point about a technique and an idea, then move on - it is the essay in the exam that forces you to write 15 paragraphs+ that will chew up most of your time!
Nevertheless, classics is my passion and its a great subject - it will really change your outlook on everything!
My texts in 2012: Iliad 16
Temple of Zeus at Olympia and its Sculptures
Herodotus and Thucydides
Agamemnon and Medea
Good luck!