[polly]

Wild Ride attacks both. It depends mostly on RNG (game randomly decides who to shoot at), but generally it will always favor other opponents, even if they are across the map.
In a 1v1 it will always shoot them though (unless they put down a summon).

If you are asking if it is intended, I'm pretty sure it is. It never specifies that the enemy you are riding is an exception. It just fires at a random opponent for every tile moved forward.