Prepare grill to medium-high heat.
Place potatoes in a medium saucepan; cover with water. Bring to a boil. Reduce heat; simmer 10 minutes or until the potatoes are almost tender. Drain and rinse under cold water; drain well. Place the potatoes in a bowl. Drizzle with 2 tablespoons of Honeyed Lemon-Dijon Vinaigrette; toss gently to coat.
Place potatoes, cut sides down, on grill rack coated with cooking spray; grill 3 minutes on each side or until potatoes are very tender.
Combine potatoes, arugula, and remaining ingredients in a large bowl. Drizzle with remaining 6 tablespoons Honeyed Lemon-Dijon Vinaigrette, and toss gently to coat.