While crust is cooling, combine pears, honey, grape juice, and salt in a medium pan. Cook over medium heat, stirring frequently, until pears are tender, about 5 minutes. Transfer to a large mixing bowl and let cool. Add raspberries, vanilla, flour, and 6 tablespoons sugar; stir gently to blend. Transfer filling to pie crust. Roll out second pastry disk and arrange on top of pie. Fold edges of top crust over bottom crust, press edges together, and crimp. Cut eight slits, about 1½ inches long, in top crust, radiating outward from the center.