Preheat oven to 450 degrees F. In a medium bowl stir together all-purpose flour, whole-wheat flour, baking powder, thyme, garlic, cream of tartar, and salt. Using a pastry blender, cut in cream cheese and butter until mixture resembles coarse crumbs. Stir in 3 tablespoons of the Monterey Jack cheese. Make a well in the center of the flour mixture. Add milk all at once; stir just until dough clings together.