Make the Earl Grey simple syrup: Pour the boiling water in a liquid measuring cup, add the tea and steep for about 5 minutes. Remove the tea and gently but tightly wring out the liquid from the tea bag or shake the tea infuser to extract as much liquid as possible. (Discard or compost the tea.) Stir in the agave until fully dissolved and let cool completely. You should get a generous ¾ cup. If not using right away, transfer to a bottle or lidded container, and refrigerate until needed.
Make the margarita: Chill two rocks glasses in the freezer for 5 to 10 minutes. Meanwhile, make a small pile of salt on a plate. Cut a wedge off of one of the lime halves, and thinly slice the remaining lime half into wheels. Rub the lime wedge around the outside rim of the glass, then roll that rim gently over the salt to create a salt edge. Fill the glass with ice, and repeat with the other glass.
Fill a cocktail shaker with ice, stir together the Earl Grey simple syrup, lime juice and smoked paprika until thoroughly chilled and diluted, about 15 seconds. Taste, and add more smoked paprika, if desired. Strain into the prepared glasses, garnish each with a lime wheel and serve immediately.
