It is always best to have the property owned under the low income earner as the Australian tax system is a progressive tax system. For example, the high income earner maybe paying tax at 46.5% rate (including medicare levy). Whereas, the low income earner maybe paying 33.5% rate (including medicare levy).
Essentially, lets say the investment property earned you $5000 in net rental income.
High income earner will pay $2325
Low income earner will pay $1675
This works the same way if the property was sold and capital gains tax was involved.
(Ofcourse there are tax offsets and other tax implications but this should give you the brief idea)
However, ideally the best advice depends on the situation and your family structure/income.
Always best to consult an accountant for advice before making any financial move.
Long story short do not try to find the best tax benefits/deductions always try to find the best way to minimise tax payable "legally" :)
Hope this helps!
The dilemma with the above answer is the issue of negative gearing.
If the purchase is negatively geared then you want the property in the name of the taxpayer with the highest income.
In the utter , if you have paid down the loan this will cause a tax problem.
A unit trust structure may allow you to have your cake now and then have your cake in the future as well because there is a strategy with this structure for overcoming this problem.
Take professional advice!