Make the vanilla simple syrup: Combine 1 cup sugar with 1 cup water, plus one scraped vanilla bean. Bring to a simmer over medium-low heat; stir until all of the sugar as dissolved. Let cool.
To a large bowl or pitcher, add the gin, Cappelletti, juices, and cooled simple syrup. Add slowly and taste as you go (you may not need it all). Stir to combine.
If serving, immediately, add several ice cubes to chill. Top up with sparkling wine and garnish with orange wheels. If making ahead up (up to one day), bottle and refrigerate, reserving the sparkling wine until the last minute.