Not everyone who works at a bank is a "banker" -- going after bonus structure holistically without regard to station/role seems impractical bordering on impossible.
Beyond even that, one might imagine that if US banking regulations get extremely prohibitive, banks will just move offshore. (And still be too big to fail with regard to the US economy)
I think that a little divide-and-conquer is needed to fix some of the smaller sub problems...
Part of the issue you're highlighting has to do with banks being able to engage in risky behavior - the traders that argued, after the collapse of, say, AIG, argued that they still deserved their bonuses. End the mixing of risky and non-risky behavior and you put most of that problem to bed.
Banks moving offshore isn't really realistic - you can't avoid, at the moment, having America as part of your bank - too much of a market. So even if, like UBS, the bank isn't in the US, it doesn't mean that they wouldn't be subject to regulation.
Beyond even that, one might imagine that if US banking regulations get extremely prohibitive, banks will just move offshore. (And still be too big to fail with regard to the US economy)
I think that a little divide-and-conquer is needed to fix some of the smaller sub problems...