The techniques of sparkling winemaking did not originate with the Benedictine monk Dom Pérignon, nor was the first purposely sparkling wine produced in the region of Champagne. Regardless, through centuries of refinement Champagne has become the world’s leading sparkling wine and the vinous embodiment of luxury and celebration.
I may be wrong but I think there are currently 8 AOP regions for Cremant wines produced by the traditional method? Cremant de Savoie was promoted an AOC status in 2015 if not mistaken.
There's discussion on this in the comments on the Vin de Savoie AOP page in the Compendium. Seems as though Cremant de Savoie is a designation within that AOP, rather than its own appellation. The Cahier des Charges reads as such and the Savoie study guide implies this.