For rice: In a small saucepan, bring the rice and water to a boil. Cover, reduce heat to low and simmer for 30-35 minutes until the rice is tender. Stir in the cilantro, lime juice, garlic, salt and pepper.
For pico de gallo: Combine the tomatoes, red onions, jalapenos, lime juice, cilantro, salt and pepper in a small bowl.
For avocado crema: Combine the avocado, yogurt, lime juice, water, cilantro, salt and pepper in the bowl of a food processor. Puree until smooth.
For grilled vegetables: Preheat a gas or charcoal grill on medium high heat.
Stir together the olive oil, cumin, paprika, chili powder, onion powder, garlic powder, 1 teaspoon kosher salt and 1/2 teaspoon black pepper in a small bowl.
Coat the zucchini, squash, peppers and corn in the olive oil-spice mixture.
Grill the vegetables until they have grill marks all over, about 5-7 minutes for the corn, turning occasionally, about 3-4 minutes per side for the zucchini and squash and about 2-3 minutes per side for the peppers.
Let the veggies cool for a few minutes. Dice the zucchini and squash. Cut the peppers into thin slices and slice the corn kernels off the cobs.
To assemble the burrito bowls, spoon the grilled vegetables, rice, pico de gallo and black beans into individual bowls. Top with avocado crema, chopped cilantro and a lime wedge.