LED driver putting out more voltage than rated?
The power supply for the Hue spots is a constant voltage DC supply.
The power supply is not an LED dimmer.
The Hue hub communicates directly with each spot via ZigBee.
I assume each spot has RGBW LEDs and each requires at least 4 dimmers.  This means a single PWM dimmer could not possibility control the Hue spots.  

You only need to use a higher wattage DC power supply than the one supplied by Phillips.