Della has given you the perfect answer on this, Adam. It is indeed Imperial's "Fashion" punch top and base - plus two extra bases. To the best of my knowledge they were not sold separately (they were certainly not shown in any contemporary ads as separate items). Imperial did not market the bases as vases, but of course, how they are used in practice is entirely up to the owner. Carnival was generally marketed to have as many possible uses as possible...all the better to sell!
There are some punch sets that were actually made with intentional multi-purpose bases. Dugan, for example, made a punch set called "Many Fruits" by collectors, that had a base that "doubles" as a comport. Dugan also made a punch set known as "Stork & Rushes" which did indeed have a base that they marketed as a true vase. It is called "Summer Days".
I have written the above paragraph and there is more about "Fashion" in this thread.http://www.glassmessages.com/index.php/topic,4068.0.html
Yes, the set is complete with 6 punch cups. These would have originally hung from the sides of the bowl by twisted wire hooks. As Christine says, perhaps you should get them. But bear in mind you will then have a full punch set plus two spare bases.
The colour is marigold and it is "old" Classic Carnival Glass. "Fashion" is almost always found in marigold. It's possibly the most available Carnival punch set in existence (with the exception of the Indiana "Harvest" one from the 1970s).