If one pom pom is a pom pom does that make two pom poms pom pom pom pom?

No. Many people believe that pom-poms should have a "plural-plural." But, "pom-poms" is the same, whether it is one set or a hundred sets. If there are two or more pom-poms its just pom-poms.

As a comparison, it would be like asking if one dog is a dog should two dogs be referred to as dog dog.

Also, the singular of pom-pom is pom-pom. It comes from the French Word pompon. Although some people will tell you that the singular is just "pom," this is not true. You can have one pom-pom, or many pom-poms.