Using 200w amp with 300w rms speaker

The recommended power for the CM10 is 50-300 watts with 8 ohm impedance. Sensitivity is 90dB, although independent measurements reveal a sensitivity of 88.5dB. Your amp is very capable of driving these speakers.
I couldn’t find the impedance curve across all frequencies, but the reviewers state that these speakers are easy to drive. Even if impedance dipped down to 4 ohms your Mac would still be able to handle the load.
You should ask the dealer to confirm.

The power requirement of a speaker is not measured as RMS. You should check the specs of the Focals again.

Copied from Enjoy the Music review.

Specifications
Type: Three-way vented-box system
Drivers: 1" decoupled double-dome aluminum high-frequency
            6" woven Kevlar cone FST midrange
            Three 6.5" paper/Kevlar ® cone bass
Frequency Response: 45Hz to 28k Hz (+/-3dB)
Within 2dB of reference response
Horizontal: Over 60°
Dispersion: Vertical over 10°
Sensitivity: 90dB/W/m
Harmonic Distortion <0.5% 110Hz-20kHz
Nominal impedance: 8 Ohm (minimum 3.2 Ohm)
Crossover Frequencies: 350Hz and 4kHz
Recommended Amplifier Power: 30 to 300 Watts into 8 Ohm
Dimensions: 42.8" x 14.4" x 14.3" (HxWxD)
Weight: 73.7 lbs.
Finishes: Rosenut, gloss black, and satin white
Grille Color: Black or Grey (with satin white finish only)
Price: $3999.99 per pair

30 to 300 wpc amplifier recommendation gives you a wide range of amps to work with.  Your Mac at 200 wpc should be absolutely fine with the CM-10 S2.  If one was pushing an amp to run at 200 wpc continuously then one is headed towards hearing loss or already suffers from it and might be better served by high efficiency Horn speakers or much larger floor standing speakers that can absorb that steady power input without blowing voice coils apart, especially on transients.  Not to mention there’s little headroom left from the amp at peak rms so clipping will be destructive.  At sane listening levels and average sized rooms the Mac / B&W combo should be more than satisfactory. 

The power recommendation is for MAXIMUM safe power.

To gauge the power needed, look at the sensitivity rating instead.

Doubling the watts on an amp will give a mere 3db more power. Going from a 200 watt amp to a 300 watt amp will give less than 2db more power. I don’t think that you should worry about it!