The last few times that I've locked the car, the spare tire courtesy light is lit up when I walk away. It goes out with the interior lights, so I wasn't concerned with it, but I am curious; can anyone confirm if that light is tied to the valet timer in the car? 

yes it is on mine too. noticed it one night and thought something was wrong until it went out.

The spare tire light will come on with the interior courtesy lights, so, yeah, it is normal. Weird, but normal. Weird kinda like the hood light on a Cadillac will only come on with the engine running(hood open)....what good is that if your trying to figure out why the engine died on you at night?
The theory on the spare tire light is so the light will be on if you need to remove the tire. You don't have to leave the door open, just turn on the interior lights. It also helps with visablitly at night for people flying by you while yer trying to change the tire.