To make simple syrup: In saucepan, combine sugar, hot water and orange zest; heat 3-5 minutes until sugar is completely dissolved. Set aside and let cool.
To make cocktail: In cocktail shaker, combine orange juice, pomegranate juice, vodka or gin, lime juice and orange simple syrup. Add ice, shake and strain into tall glass over fresh ice. Top with club soda.
Garnish with orange slice, pomegranate seeds and fresh rosemary sprigs, if desired.