I am attempting to retopo a face using bsurface, this is working ok for now but i would like to know if it is possible to ajust the position of the vertecies while it is snaped to the face the shrinkwrap modifier seems to be working only for bsurface and for now i can only move vertecies freely which is not good, i would like them to stick to the head no matter where i move them.
I suppose you don't see your vertex sticking to the surface because of the modifier setting: you should activate Display Modifier in Viewport and Display Modifier in Edit Mode so that you can see the original mesh and its modified version, and put a bit of Offset if you want to see it out of its Target surface.
Also, I'm not sure about the Snap option, as you already use the Shrinkwrap modifier. I guess you should either use the Snap or the Shrinkwrap method. If you use the Snap option, select Face as Snap Element and activate the other Snap options.
I suggest you look at this video on YouTube about how to set up Blender for retopology: https://youtu.be/2hEHtKH55Us