Heat olive oil in a 12-inch heavy skillet over moderate heat until hot but not smoking, then cook sausages, turning over once, until well browned, about 8 minutes total.
Add grapes and cook, stirring occasionally, until sausages are cooked through and grapes are softened, 10 to 12 minutes. Stir in vinegar and salt and pepper to taste.
Meanwhile, melt 2 tablespoons of butter in another large skillet over medium heat. Saute the garlic for two minutes. Add the spinach and saute until heated through. Season the spinach, to taste, with salt and pepper. Add raisins and pine nuts.