In a medium skillet, cook bacon over medium heat 6 to 7 minutes or until crisp; drain on paper towels. Crumble bacon; set aside. Reserve 2 tablespoons bacon drippings in skillet.
Add yellow onion and celery and cook on medium-high heat until onions are translucent.
In 6-quart pot (or Dutch oven) mix onion, 3 cups of the chicken broth and diced potatoes. Heat to boiling; reduce heat. Cook 10 minutes or until potatoes are very tender.
Meanwhile, in same medium skillet, melt butter substitute over low heat. Stir in gluten free flour and whisk until smooth. Add 1 cup of chicken broth. Bring to a boil and continue to let boil for 1 minute.
Reduce heat and gradually stir in 4 cups of the rice milk. Continue to cook and stir while mixture thickens.
Pour thickened rice milk mixture into potato mixture. Add the salt and pepper and ½ of the bacon crumbles. Cook over medium heat, stirring constantly with whisk, until mixture is thickened and bubbly.
Serve hot, in soup bowls, and top with remaining bacon crumbles and scallion onions.