No No...dont shoot the messenger..the bulb is just the symptom not the cause of the problem, you gotta differentiate the two. Now the typical cause of that is a deployment/impact sensor that caused it. I doubt if its a loose connection and seriously doubt your seat-belt needs to be "electronically adjusted". Did you do any recent work on the car inside? You mentioned somehting about tensioner adjustments, beware the SIDE airbags share the same circuit so if you messed with them, then they could be the cause not just the steering wheel ones. SRS is a tricky thing...you dont want it to deploy on you..one false move and the thing explodes in your face...may wanna just take it to shop
Cheers