Depends on what you think "matter" means. If you're in commerce or law and looking for a job at a big, prestigious firm, i hear coming from the GO8 really helps.
Otherwise, not really.
We've had huge discussions on this before (i'll see if i can post the links later). Rankings are a number produced by adding together whatever factors the ranking company feels like using. I could start up a ranking website, not mention how i get the ranks and make swinburne #1 because it has the most amount of red bricks. So, just caution about that.
A lot of the rankings are weighted towards research measures and financial measures, that'll hardly matter to you as an undergraduate student. There are way more things that'll affect your life as a uni student on a daily basis than rankings. Travel distance to uni, if you're really in a course thats the best fit for what you want, if they teach the course in the way you want (some places offer hands on/more practical/more industry based courses etc), student cohort, friends, uni clubs, uni services (counsellings, people to help with English, advisors, etc).
When this topic comes up, i always mention this point. On the whole, there's no hidden knowledge they wont teach you. All professors are qualified for their jobs, almost all of them have PhD's. The universities can afford to be choosey considering how many graduates there are each year. There's not some hidden knowledge the professors at UoM or Monash have that the ones at La Trobe don't. This is especially true for rather standardised subjects like the sciences and things like economics or history. If you're learning physics at UoM or Swinburne, neither will leave out quantum theory. If you're learning 20th century history at Monash or RMIT, they wont leave out WW2.
Rankings are fairly useless to you as an undergraduate student, especially very broad rankings. Monash is below UoM in overall rankings (the university as a whole 36 Vs 61) but is above UoM in Pharmacology for instance
, 6th and 9th best in the world respectively, according to the rankings. ANU is 24th in the world overall according to QS and yet 6th in philsophy
Just to wrap up, uni isn't just a job factory either. If you want that, try a tafe. It's about learning. It's about making a transition from Highschool to the wider world. There's the potential to meet a lot of people, join a lot of clubs, have a lot of fun and just generally have a good time before you wind up in the workforce.
In regards to being able to find a job in Australia? Not really.
Thank God, that's hard enough as it is..