In a small pot, combine sugar, water and ginger and bring to a boil. Remove from heat then stir in hibiscus flowers and let chill. Once cooled, strain and reserve a few hibiscus flowers for garnish. Syrup can be made in advance and stored, refrigerated, for up to ten days.
Chill all cocktail ingredients.
In a champagne flute or wine glass add white rum, lime juice, and hibiscus syrup. Top with sparkling wine and garnish with a few reserved hibiscus flowers.
