Add the peach nectar and vanilla bean syrup to a champagne flute. Top with sparkling wine and serve.;
Vanilla Bean Syrup:
In a small saucepan, combine the water and sugar. Split the vanilla bean in half and scrape off the seeds with a paring knife. Add the seeds and the pod to the saucepan. Bring the mixture to a simmer over low heat and stir until the sugar dissolves. Simmer on low until thickened, about 5 minutes. Strain and let cool completely before using.;