Yes, there is almost certainly a connection. It's considered by Carnival collectors that Fenton's Horse Medallion pattern may have been inspired by the painting "Pharoah's Horses" by John F. Herring. We also show further images of an antique copper and brass powder flask (that pre-dates Classic Carnival) in "Carnival Glass The Magic & The Mystery" that features an actual medallion design of a trio of horses' heads. It's virtually identical to the Carnival pattern.
There are many fascinating connections between Carnival designs and other objects / art / crafts / media etc. I have delved into it in depth and found it truly compelling.
GT