Maybe work out a deal with the 13 yr old. If you only have to tell him once to get up and ready for school during the weekdays, and he only sleeps in until XX o'clock on the weekends, then the time he chooses to go to bed is fine with you (the idea that he will self regulate and go to bed earlier if he finds he cannot wake in the morning).
You can also research WITH him the importance of sleep and how much sleep a teenager should get and what a teenager sleep cycle looks like, and why sleeping in (excessively) on the weekends and getting no sleep during the week is poor for his health. If he learns the information himself, he might be more willing to have an appropriate bedtime.
Encourage him to start his studies earlier in the evening, so if he gets really interested in something, it isn't as late. He also isn't as likely to miss his dinner as he is sleep - so he will learn to take a break in a subject and get back to it again later.
You and your wife feel very differently about the issue, so you need to find solutions that work with both philosophies, maybe putting some of the responsibility on your son.
Best of luck - I remember reading novels until the wee hours of the morning, and I was often very tired, but as teenagers you seem to figure out how to make it work. Hopefully though, if your child becomes more informed of how important sleep is, he'll make better decisions - I might have - but then again, as a teen I might not have :-)
State Certified Early Childhood Special Education Teacher
New Mom as of March 2009!