That seems like a very small amount of nap time to me as well. I have a 6 month old, and I know at 3 months my (b'fed) baby was sleeping approximatly like this:
6:30 wake up
8 or 8:30 nap
9 or 10 up
11:30 or 12 nap
1 or 1:30 up
4ish nap
5ish up
8ish to bed
She also woke 3-5 times through the night for feedings as well.
Now, that being said, my first child slept through the night at 3 months (8pm to 6am) and she had only 2 naps a day, each about 2 hours.
Does he eat alot at a sitting? And when he wakes, is he waking cranky or happy? Is he sleeping on his tummy or his back? Are you still swaddeling?
If he's waking cranky, you might want to add an extra nap and if you can bring yoursef to do it, let him CIO.
If he's waking happy then he must be getting enough rest.
At 3 months he should be eating 3-4 ounces 4 to 6 times a day (according to enfamil). You might also add in some cereal to see if it helps him nap more. I recommend starting with rice, it's the smoothest and least likely to have allergy issues.
If he's sleeping poorly on his back you might try letting him sleep on his tummy (provided he can lift and turn his head), since tummy sleeping is almost always sounder sleep for babies.
All in all, if he seems happy then let it be, but you can tweak it if you want. This is the age where you need to start establishing a sleep schedule, come 4 months their sleep patterns change little from there to 18ish months, so establishing a sleep schedule you can live with is KEY in the next 30ish days.
Good luck!