Tires cupping. Service adviser at VW blames bad suspension on 2009 CC. If this is true shouldn't VW make good?

Not necessarily. You will have to read the fine print in your warranty. If the warranty doesn't cover maintenance items then you are out of luck. Maintenance items usually include brakes, tune ups, oil changes, tires, etc., things that normally wear quickly. Suspension could also be considered a maintenance item because there are many factors involved in determining how long it will last before you need to start replacing suspension parts, none of which the factory has any control over. They can be held accountable if there is a flaw in the suspension such as a manufacturing defect or design flaw, but that's about it. They can't control how you drive or load the car. Bad roads (potholes,bumps) or heavy loaded or overloaded cars dramatically shorten the life of suspension. Driving habits can also factor in, especially in conjunction with one of the other two.
You would have to prove to them that it's not your fault before they would consider doing anything about it if the fine print eliminates maintenance items from the warranty. If the fine print doesn't then you will have to argue the specific parts of the warrant that you think apply to your situation. Hope this helps.