I think Honda would have a hard time proving that putting different tires and rims on the standard Civic frame would void the warranty. There are laws that cover putting aftermarket products on a car, which states that the manufacturer must still honor the warranty.

I'm not sure about the details. However, I do know that I have put new tires and rims on almost every car I have owned ever since the mid-seventies, and I have never had an issue with warranty work.