How old is your LO?
Growth spurts seem to be around 3, 6, 9 weeks then 3 months, 4 months and 6 months. There are other spurts after that but they seem to vary a bit more, and even the recognised ones can vary from baby to baby. I never noticed a growth spurt when it was happening with my two, it was more a case of suddenly noticing they needed bigger clothes! Some bottle fed babies have quite noticable GS and they can last up to a week really.
How much is your LO taking at a feed now? If he is draining feeds make sure you increase them by 1oz or 2. There should be a bit left at the end of a bottle feed so you know they have stopped because they are full and not just because the bottle is empty. Some babies will need bigger bottles during a GS and stay on the bigger bottles, some need bigger bottles for a few days and then drop back to a slightly smaller feed. If your LO is waking hungry during the night then feed, if he was STTN then he should go back to it after the need for extra calories passes. However if you can increase calories during the day it should help, either by feeding a bit earleir to get an extra bottle in or just by increasing feeds.
HTH!
Laura