Preheat grill. In a large bowl, whisk together Teriyaki Sauce, garlic powder, sesame oil and rice vinegar. Add vegetables and toss to coat. Using 6 medium squares of heavy-duty foil, divide the vegetables evenly, drizzling with remaining dressing. Fold up into packets and crimp the edges of the foil to seal. Place packets seam side up on the grill and cook for about 10 minutes. Carefully open one packet to check for doneness.