Fill a pint glass with ice. Pour in the whiskey liqueur, lime juice, simple syrup and peach schnapps. Cover the glass with the top of a cocktail shaker and shake vigorously for 8 to 10 seconds. Strain into a Collins glass filled with ice. Pour in the tea and garnish with the lemon wedge.
Combine the sugar and 1 cup water in a small saucepan and bring to a boil. When the sugar is completely dissolved, remove from the heat and cool to room temperature. Refrigerate, covered, for up to 1 week.