Dave,

Welcome to FlyerTalk!

You're all set with your stockpile of SPG points since you can either transfer them to US Air and book Star Alliance awards or to American Airlines for Oneworld awards.

You're also pretty set from a spending perspective since spending $20K a month gives you 240K SPG points a year. It is about 100K miles in business class to Europe from the US or about 80,000 SPG points (since you get a 25% bonus for transferring in increments of 20,000 points).

You could consider adding the Chase Sapphire Preferred to take care of those times when the AMEX is not accepted since you can transfer points to airlines and hotels.

The Chase Sapphire Preferred gives you double miles on travel and dining so if you are a big spender in those categories, it may be worthwhile to consider moving some of your spending from the AMEX to the Sapphire Preferred.