Looking at your routine, if he wakes at 2.30 from his nap, then 4pm would probably be too early for the catnap if he can go 2 hours between sleeps. You would be better trying for it at 4.30 and then having a bedtime more like 7pm. If he doesn't take the catnap though, then yes, go for an early bedtime. There is a good chance though that if your DS is getting 2 good 2 hour naps in the day, then he might start showing signs of dropping the catnap. Seems to me though that you have plenty of time to have a catnap though and a slightly later bedtime. Or did you particulalry want a 6.30 bedtime?
The most important thing is for your baby not to get overtired-don't worry about shedules, you just need to follow your baby's cues and if he's not tired at 4pm then you're not likely to get him to sleep.