Combine lemon juice, lemon zest, garlic, honey and dried basil in microwaveable bowl. Microwave for 10-15 seconds to loosen the honey. Slowly whisk in 1/4 cup olive oil. Set aside.
Combine potatoes, asparagus and 3 tablespoons olive oil in large Ziploc bag. Shake to coat. Spread on large baking sheet separating the vegetables. Coat ears of corn with butter and add them to the baking sheet. Sprinkle potatoes, asparagus and corn with garlic powder, onion powder, salt and pepper. Place in oven at 375 degrees. Remove asparagus after 12-15 minutes. Flip potatoes and turn corn. Return baking sheet to oven. Remove corn after 5-7 more minutes. Return potatoes to oven and cook for an additional 10 minutes or until fork tender.
Remove corn kernels from husk. Combine cooked potatoes, asparagus and corn with tomatoes and red onion. Whisk lemon vinaigrette and drizzle over vegetable salad. Gently stir to combine. Refrigerate leftovers.