Irises are only eligible for American Iris Society awards if they are originally introduced in North America.
Many Cayeux irises make their way to North America, but not surprisingly, they are introduced in France. I don't know if the French have their own award system or not, although it appears not. They have their own version of the Dykes Medal, but haven't awarded it since the 1930's.
Decadence won AIS awards because it was originally introduced in the spring of 2004 by Keith Keppel in Oregon, then by Tempo Two later that year. Keith introduced a number of Barry's irises over the years. Decadence might have won the American Dykes Medal, but there's an additional requirement for that, the iris must be hybridized in North America as well.
