Soreness behind ear on top of head and next to temple ride my bike about 30 km to work everyday with a bag on my back - could it be neck problem?

Tension. Could be muscle tension from the bag transmitted to that area, however given the location. Near the temple you need to see your doctor to rule out a potentially dangerous condition called temporal arteries which can affect your vision. If left untreated can cause blindness on the side which is irreversible.