Todd, the first comment is that it would seem to be unlikely that you're using the maximum power capability of your 352 and need to be concerned about still more. Be that as it may, what you've described isn't "bridging", and wouldn't result in any additional power capacity being available. Connecting say the left channel power terminals of the 352 to the left speaker would use one of its 80 watt rated channels. Using the right channel pre-out of the 352 to drive one of the 214's power amps would result in the same power being available to the right speaker(and the same as the 352 alone).
Bridging(which the 352 doesn't have built-in provision for)requires feeding both positive terminals of two amplifier channels into the positive and negative terminals of a speaker. The polarity of one of the output channels has to be reversed by 180 degrees so that the two channels add together rather than running head-on into each other in the speaker and cancelling. If the receiver or amplifier doesn't have built-in circuitry to do this polarity reversal(it can't be done by switching wires or anything else simple)there are separate items available, often referred to as "inverters" to accomplish this. If two voltages are fed into the speaker instead of one, theoretically the power could be as much as quadrupled, since power is proportional to the square of the voltage and twice the voltage would yield four times the power. Of course the process isn't completely efficient and the typical result is about triple the power capacity. It's your call, but it'd be better if you haven't actually bought the 214 yet.
