Those are normal parts of the map, just as unshaded polygons without textures. Like the one on the right, normally that's a lamp hanging down from a wooden post holding it.
It's most likely either a problem from when you patched to the Vi patch or just a problem with your graphics card. You could be able to solve it through the client repair option. If that doesn't work send in a support ticket with your hardware specs and that screenshot, see what Riot has to say.
EDIT: Yep, they're in the exact same spot, just with pretty wood textures in my game. Some texture file probably just got corrupted for you.