I think you either used too much wood in the smoker or you should check airflow in your smoker.
I use citrus, including orange, on poultry whenever I can. My brother brings a load up every spring lemon, orange, tangerine, grapefruit, and lime. I have never had bitter tasting chicken using any citrus. A pleasant medium smoke flavor with a hint of sweet smoke.
Humphrey's DownEast Beast W/BBQ Guru