Just a minor quibble: The Typhon Pact is an alliance, not a state. It's a closer alliance than most, given the common currency, but it's not a state in its own right, either, as Bacco made clear during her press conference. Think of it as being like the difference between the US and the European Union.
I'd call it a state-like entity if not a state. For me, the kicker is the matter of the shared currency. As events in the Eurozone are suggesting, it's difficult to maintain a common currency without a common economic government. Mundell's writings on optimum currency zones are surely common knowledge by the late 24th century. With the Breen and Tzenkethi on one side of the Federation, the Romulans on another, and the Tholians and Gorn and Kinshaya scattered on the Klingon Empire's fringes, the Typhon Pact is going to need some very close cooperation if it's to avoid its new currency imploding.