Married here is Australia ( ;
If we are talking about the personal income tax then no. I know in other countries it is possible to split your income and that would effectively reduce your effective tax rate as a whole, but that doesn't apply in Australia.
If anything you could be both worse off, you need to be careful that if your wife-to-be has some sort of Centerlink (social security) benefit, she may no longer be eligible for it once married to you, if you hold a full time job, make sure you check this.
There are other decisions you can both make as a couple, which reduce your taxable income, revolving around salary sacrificing, negative gearing, to name a few. But that's something else, although in some circumstances it may be tax-wise beneficial to be married, I wouldn't say that to be the general case.
Some things such as ambulance cover, you can get as a couple, reducing your costs slightly, but I can't imagine savings running into the 1,000s of dollars, more like low hundreds if that.
Consult a tax professional for any other queries you have.