Hi Mike
Under the older Apple application iChat you could group conference up to 5 individuals I believe I myself did with three.
Under FaceTime it is only one on one. Although I have been able to Facetime from my Mac to one, Facetime from my iPad to another, and Facetime to one more via Facetime on my iPhone all at the same time. I can see all three on the three devices but they only see me.
Microsoft owns Sykpe now. Skype does have Group Conferencing. I have not tried it for a group, but have used it from time to time with PC Window friends, and the video is pretty good.
I emailed Tim Cook before Christmas and complained that FaceTime did not have the capability to video conference like Apple's previous iChat application would. Of course no reply.
Best
Mike