Scrub the potatoes and cut them into ½ inch dice. Bring a medium pot of salted water to a boil over high heat, add the potatoes, cover the pot partially and return the water to a simmer, then reduce the heat so that the water stays at a simmer. Simmer for about 15 minutes until the potatoes are fork-tender. Drain the potatoes but do not rinse, and let the potatoes cool for about 10 minutes in the colander.
Meanwhile in a small bowl mix together the onion, yogurt, buttermilk, mustard, lemon juice, zest, and salt and pepper.
Place the potatoes, corn, basil, and bacon in a large bowl, pour the dressing over and toss to mix well. Turn into a serving bowl.