Mix together the brandy, sherry, lemon juice, simple syrup, liqueur, port and some lemon and orange slices in a festive pitcher. Cover and chill for at least 1 hour and up to 24 hours. Right before serving, add the sparkling wine.
To serve, fill ice-filled festive holiday glasses three-quarters full with punch, then top off with club soda. Garnish with some of the soaked lemons and a few pomegranate seeds.
To make simple syrup, boil equal parts sugar and water in a saucepan until the sugar is dissolved. Let cool completely before using.