Whisk together sour cream, lime juice, and cilantro in a small bowl until smooth, then refrigerate until ready to serve.
Heat olive oil in a large skillet over medium-high heat, add the diced chicken, chipotle peppers, cumin, and garlic powder, and cook for 12 to 15 minutes, stirring occasionally, until the chicken reaches 165°F / 74°C and is lightly browned.
Divide the chopped romaine lettuce among 4 bowls as the base layer.
Top each bowl with cooked chicken, black beans, and pico de gallo, arranging them in separate sections.
Drizzle the cilantro-lime dressing over each bowl and serve immediately.