Prepare the mango salsa by mixing diced mango, red onion, jalapeño (if using), lime juice, cilantro, and a pinch of salt in a bowl. Stir until well combined, then refrigerate while preparing the rest of the dish.
Make the lime-chili sauce by whisking together Greek yogurt, mayonnaise (if using), chili powder, lime zest, lime juice, honey, salt, and pepper until smooth. Adjust seasoning to your preference before setting aside.
Cook the shrimp by patting them dry and seasoning with chili powder, garlic powder, salt, and pepper. Heat a grill pan or skillet over medium-high heat with olive oil; cook each shrimp for about 2-3 minutes per side until pink and slightly charred.
Assemble the bowls by placing a scoop of cooked rice or quinoa at the bottom of each bowl. Top with grilled shrimp, sliced avocado, and spoonfuls of mango salsa.
Drizzle with lime-chili sauce and garnish with chopped cilantro. Serve immediately with lime wedges.