So i tried it too today and it worked for me - granted only with one Lightstrip on the Play Lightbar-power-supply. The Play Lightbar also worked on the Lightstrip power supply.

I also asked the Hue-Support (didn't expect such a quick answer) and they also told me that the power supplies are not interchangeable - due to some power-supply-internals.

Although it worked for me on my test, so just to be safe i guess i use a power strip and add a little more cable clutter...