In a large skillet cook the bacon over medium heat until crispy. Remove the bacon, drain on paper towels, and crumble. Carefully pour away all but about 2 tablespoons of the bacon grease; return the pan to the heat, and add the onions. Cook about 3 minutes. Add the turnip greens and cook 8 to 10 minutes. Add the Alfredo sauce, cream cheese, salt, pepper, and garlic powder. Cook until the cream cheese has melted and the mixture is bubbly. Stir in the crumbled bacon.