Bone meal is a good plan after repotting. NPK ~ 0-10-0 Phosphorus is a good additive to promote strong root growth.
http://www.vitasoil.com/bone%20main.htm
http://www.westsidegardener.com/howto/fertilizer.html
I usually don't fertilize established bonsai a heck of a lot in late winter and early spring when I do most of my repotting. The spring flush of growth is already more than I can handle. After pinching begins, I usually come on strong into the defoliation period in early summer.
Regards,
Matt