Warm broth in a small saucepan over medium-low heat.
Heat oil in a large saucepan or stock pot over medium-high heat. Cook onion for about 5 minutes, stirring, or until softened. Stir in barley to coat with oil and cook for 1 minute.
Add wine to pot and cook for 2 minutes, or until liquid is almost completely absorbed. Reduce heat to medium. Add 1 small ladleful of broth (about ½ cup) and cook, stirring until broth is absorbed, about 3 to 5 minutes. Continue adding one ladleful at a time, as liquid gets absorbed and barley has cooked for 26 to 30 minutes. Add any remaining broth and ½ cup water. Reduce heat to medium-low and cover pot. Cook, covered, for 10 to 12 minutes, stirring every 4 or 5 minutes. Stir in yogurt and Parmesan cheese.
Meanwhile, cook bacon in a large nonstick skillet over medium-high heat for about 8 minutes or until crisp. Remove to a paper towel-lined plate with a slotted spoon.
Add Brussels sprouts to skillet and sprinkle with salt and pepper. Cook, stirring, for 5 minutes or until lightly browned. Reduce heat to medium if pan gets too hot. Stir Brussels sprouts and bacon into barley mixture and serve immediately.