First make the simple syrup. In a small pot, combine the pomegranate seeds, sugar and water. Bring to a boil and allow to boil for 5 minutes until the sugar dissolves. Strain and discard seeds. Allow to cool while making the rest of the sangria.
In a large pitcher, add the fruit, red wine, St. Germaine, Grand Marnier and pomegranate juice. When the syrup is cool enough, add that as well and mix.
Chill for at least 2 hours and when ready to serve, pour in glasses and top with sparkling wine (or water) and garnish with pear slices and pomegranate seeds.