We're not sure how to calculate it but we did some crappy math and it got us around 6.2 lumens per watt. Again, we're not sure if this is correct. You can use the following datasheet if you'd like to calculate it yourself.
http://www.adafruit.com/datasheets/FLR-100WAS-RGB.pdf
Overall, it's decently bright but not as bright as a normal light bulb.
If you're running them at full power, I calculated 9.9lm/W by adding the typical mcd values (3700mcd), plugging them and the 50deg beam angle into [0] to get 2.178 lumens, then dividing by the summed power rating (220mW). Of course, this is ignoring the power used by the bluetooth module, Arduino, and waste heat in the power supply.
For comparison, an incandescent bulb is 15lm/W, while the Hue bulbs are 70.6lm/W. So it's no Hue replacement, but still a cool, fun project.
Thanks for the thorough calculations, it'll definitely help us moving forward. Also, glad you mentioned Hue bulbs, we were focusing on Bluetooth as our main differentiation factor but we have to cover the basic as well i.e. good lighting.
Overall, it's decently bright but not as bright as a normal light bulb.