How do you calculate watts per channel?

If you vertically biamp a speaker with two monoblocs at 100 wpc each monobloc, is the resulting watts per channel 100 wpc or 200 wpc?

I know that If only one monobloc is driving the same speaker, the wattage is 100 wpc.

If you tri-amp with the same speaker and monoblocs, will the rated wpc 300 wpc?