Would agree it's probably more than the bees wax and to check wick size and material. I've got and have had bees wax candles that have been fine but, yes, I can't see why you couldn't mix the two melted waxes. How are you making the candles? Dipping? Moulds? Rolling sheets? I don't know enough about candle making but I imagine that you'll need to check how the mix responds e.g. if you want to roll, the bees wax sheets are soft enough but the addition of petroleum wax might make them crack.
H