Could a spider bite in the ear cause jaw pain similar to getting punched?

Yes: Time to see/call a doctor. Take Benadryl (diphenhydramine) 25 mg and/or Zantac 150 mg in the meantime.

Quite Possible: I have not come across this, but it is possible. A spider bite typically causes a localized inflammatory response. The tempromandibular joint of your jaw comes into close proximity to your ear and thus could feel like jaw pain. If you already clench/grind your teeth, that area is already irritated and thus the spider bite could have made this discomfort more noticeable.

Possible: Possible. Once the spider bite treatment and resolution, jaw pain should subside. If not, see oral surgeon.