I think its just in your head. I'm 25 now, but back when i was like 14, 15yrs old, and was starting to smoke weed on a regular basis, my friends and I swore, that if we smoked a cig right after smoking a bowl, that it got us higher, but I soon realized that we were just being stupid, and we were just really high in the first place, the cig had nothing to do with it. We even tried to come up with stupid scientific sounding reasons as to why, but it was all BS lol so yea, like i said, i think its just in your head, i could be wrong, but it makes no sense to me (i'm an opiate user of 4yrs) that cigs amp the effects up. They never have for me. I do enjoy that first cig tho, after the opiates kick in ! especially back in the days of smoking OC's.
EDIT - And just for the record, i could be wrong, there could be a real effect for you, I just dont see what it could be and have never experienced it......Just wanted to clarify that I wasn't saying your completely wrong, or stupid, or something like that.