Brown the bacon in a large pot over medium heat. Drain grease, and place onion in the pot. Cook and stir until tender. Pour in the water. Mix in the bouillon cubes until dissolved. Stir in black-eyed peas, and season with salt and pepper. Bring to a boil, reduce heat to low, and simmer 45 minutes.
Place the potatoes in the pot, and continue cooking 15 minutes, or until beans and potatoes are tender. Serve warm.