There are dozens of ways that would work, with varying degrees of success.
You could use blob size to determine your angle to the front of the light. (Yes, yes you can. We've done it.)
You could track multiple lights with a single camera simultaneously.
You can track multiple lights with a single camera by switch back and forth between them.
You could track one light while dead reckoning. With 2 positions and distance measures to the same light, along with the distance of traveling, and angle from the light you can triangulate with reasonably good accuracy.
You can drive the arc of a specific distance of the light until you lose the camera tracking. This is very repeatable (you move along at the same distance from the light until you pass the "event horizon" of the light).
Basically, to be able to score on any post in auton, you MUST have a way of determining your position relative to the racks.
To be able to score only on the spiders under the lights is significantly easier, and I suspect you'll see far more of this in the early competitions.
The neat part about this whole thing is that while I've given you a good number of ways to do what you want - I haven't told you how we're going to do it
