Place bacon in large skillet and cook over medium heat until brown and crisp, turning periodically, about 8.
Transfer to paper towel-lined plate, and once cool, crumble into small bits.
In blender or food processor, pulse avocado, yogurt, lemon juice, basil, parsley, chives, garlic, and olive oil until thick mixture forms.
With motor running, add water 1 tablespoon at a time in a slow, steady stream until dressing reaches desired consistency.
Season with salt and pepper.
Cut head of lettuce into 4 wedges and place on 4 plates.
Sprinkle with tomatoes, red onion, and crumbled bacon and drizzle with green goddess dressing.
Serve immediately.