I couldn't imagine taking a hit of tobacco mixed with weed out of a bong. That'as harsh on the lungs with the tobacco mixed in. Tobbacco isn't meant to be taken in big hits like that, and my guess is the overdose of nicotine. A case of too much being absorbed in the lungs at once.

If you aren't a regular tobacco smoker, then I'm sure it was the nicotine that did it to you. It's the same effect of someone smoking while on the patch. It's too much entered into the bloodstream at once which results in dizzyness and blacking out.

I wouldn't worry too much about it, but avoid tobacco in a bong or pipe. It's better with a joint as you can control the hits, but with bongs and pipes, it's easy to take too much in at once.