Pour boiling water over lemon-flavored gelatin in a glass measuring cup; stir to combine. Stir in gin. Pour mixture into sixteen 2-ounce cups. Arrange cups in muffin tins, tilted to one side.
Refrigerate until set, about 4 hours.
Combine 1 1/4 cup sparkling wine and unflavored gelatin in a small pot. Let sit, about 3 minutes. Heat over low heat, stirring constantly, until gelatin is dissolved, 3 to 5 minutes. Add remaining 1/2 cup wine and food coloring; stir to combine.
Remove muffin tins from refrigerator. Set cups upright; pour wine mixture over lemon mixture.
Return to the refrigerator and chill until set, about 4 hours.