Well, 'robbery' usually means that you stand no chance of ever seeing whatever has been taken again, whereas the bailouts are, in most cases, closer to a low interest loan (and in the case of RBS and Lloyds, potentially a money spinner when they're re-privatised in about 5 years) than the banks simply being given an enourmous pile of money and running off with it.
If you're referring to the obsecnities like Fred the Shred's pension, and the ongoing payments of bonuses etc, I'd agree that the Treasury in particular has been absolutely shite at picking people's contracts apart, but then if they'd simply turned round and refused to pay, all those concerned would be straight into court with lawsuits they'd win, costing the taxpayer even more becuase we'd be saddled with the court costs too.
However, the banking 'bail out' isn't simply throwing money into a black hole that it will never appear from again, which is what you're implying.