Finely grind the mustard seeds in a spice grinder. Transfer to a medium microwave-safe bowl. Stir in dry mustard, maple syrup, salt, and garlic powder. Stir in the wine and vinegar until combined. Microwave on 100% power (high) for 3 minutes or until thickened, stirring every minute. Cool slightly. Transfer to a blender; cover and blend for 30 seconds. Cool.
Transfer to airtight storage containers. Cover and chill up to 1 month.