The JVC is rated 30 watts per channel @ 4 ohms. Since this is a dedicated amplifier that in theory should have a curve to match the tonal characteristics of the speaker, RMS is really not relevant. I can't imagine JVC doing a great deal of engineering on dedicated amplifiers like say Harod Beveridge did with his wonderful electrostatic loudspeakers from the 1970's. But cNet says that this seems to be a basically honest 30 watts and I have no reason to doubt that. Based on the size of the drivers, I would guess they amplifiers begin to roll off bass at about 100-120hz which is where the dedicated woofer cuts over. In theory, this would provide more power and better response than a true 25-50 watt RMS amplifier connected to the same drivers.
All of that to say, amplifier power on a soundbar, HTIB or even inexpensive audio system is a relatively worthless measurement and will mean little or nothing in the real world.