the tax creds forms will ask for your wifes details and yours, and it will ask who is making a claim, just tick the box that you are and leave your wifes box unticked.

the fact is your wife could claim the benefits in her name and is entitled to becuase she is married to a british citizen, but some UKBA staff dont know the rules and regs, so to minimise the risk of wasting time and money trying to sort any problems out if your wife claimed it, just claim it in your name