If just one Snickers bar fixed you it wasn't much of a bonk.
Generally the bonk doesn't hit me until around the 3 hour mark. When it hits I get shaky feeling and cold sweats and don't feel like I can continue on. Then I'll eat anything in sight. Convenience stores used to have little fried pies - a day's calories worth of fat and sugar in a pastry wrapper - they were perfect.
I guess that everybody's different but a pancake breakfast is guaranteed to put me into a bonk in 3 hours. I do much better with eggs, bacon and hash browns.