No you can't, power is dependent on three things:
1) The voltage output of the amplifier.
2) The impedance of the speaker.
3) The capability of the amplifier to supply enough current to the speaker.
By bridging two amplifiers you can double the voltage output and supply twice the power to twice the impedance, but the actual power is just the same. (such as 100W in 8 ohms instead of 2x50W in 2x4 ohms).
Assuming the amplifiers can be paralled (which many can't) doing so would provide twice the power in half the impedance - so for the example above it would be 100W in 2 ohms.