Wirelessly posted (BlackBerry: BlackBerry8530/5.0.0.601 Profile/MIDP-2.1 Configuration/CLDC-1.1 VendorID/417)
It really depends on what you want from a credit card: free flights? free hotel nights? cash back?
And unless your wife will be charging tens of thousands of dollars a year, the credit-card sign-up bonuses will be far more significant than the points/miles your wife will earn from just the credit-card charges.
Tell us more about what you want, and we can give you better advice.
Welcome to FT!