Preheat the oven to 425°F.
Place the diced sweet potatoes on a large baking sheet.
Drizzle the sweet potatoes with 2 teaspoons of olive oil. Sprinkle with ½ teaspoon chili powder, ½ teaspoon garlic powder, ½ teaspoon cumin, smoked paprika, ¼ teaspoon salt, and black pepper.
Toss the sweet potatoes until evenly coated, then spread them into a single layer.
Roast for 22–25 minutes, or until the sweet potatoes are tender and lightly browned.
While the sweet potatoes cook, pat the chicken breasts dry with paper towels.
Season the chicken with the remaining 1 teaspoon chili powder, ½ teaspoon garlic powder, ½ teaspoon cumin, onion powder, and remaining ¼ teaspoon salt.
Heat the remaining olive oil in a large skillet over medium heat. Add the chicken and cook for 6–7 minutes per side, or until the thickest part reaches an internal temperature of 165°F.
Transfer the chicken to a cutting board and let it rest for 5 minutes. Slice or dice the chicken.
For the sauce, add the Greek yogurt, salsa, lime juice, water, chili powder, garlic powder, cumin, and salt to a small bowl. Whisk until smooth and creamy.
Divide the romaine lettuce between 4 bowls. Arrange the roasted sweet potatoes, chicken, black beans, corn, cherry tomatoes, red bell pepper, red onion, cheese, and cilantro over the lettuce.
Drizzle each bowl with the creamy Tex-Mex yogurt sauce and serve with fresh lime wedges.