The RBA are independent of the Government. With new laws coming in allowing lenders to switch next year for free, I don't think the banks are game to risk upsetting customers by raising rates without an interest rate increase. That is a sure fire way to see people moving to credit unions.
The banks also have no reason to raise rates, at least not yet. Their profitability might get hurt, but welcome to the real world of business where your profit margins are squeezed by higher costs and competition outside of a cartel.
The article by Joyce also explains how the RBA act as a liquidity buffer for the big 4 banks. It just goes to show how the banks' credit rating isn't really all it's cracked up to be... If the RBA bail out banks with liqudity problems, why not other public listed companies and small-medium businesses?
The banks will come undone one day, I'm waiting for the right moment to short them... a recession here, or high interest rates is enough to pop the property bubble and hurt the banks. They are in way too deep with no buffer.