Not a good idea, especially through an intersection. Think about when you wait in the left turn lane in your car, and a bus comes the other way, going straight. What side of the bus do you see? The left (driver) side. If someone is on a bike behind the bus, towards the left side of the lane, you can easily see him/her from your car. If the cyclist is behind the rear right corner of the bus, you won't know the cyclist is there until much later, possibly even not until after you have started your left turn across oncoming traffic lanes.