Dear brother,
I know the san fransico CFC church was planted by Sandeep Poonen, he stepped out of a mega church to start a house fellowship and God has blessed it now, they still meet in homes.
In loveland, colorado, Santosh poonen with another elder started in a church building, he is still an elder there and the church is growing.
There is a CFC church in altanta, georgia, we attended there as a family for one year. The elders are not related to Zac Poonen, I personally never asked how the fellowship began, I know they started in a home of the Elder Sabu, and now they gather in a church building.
I believe each of these fellowships choose to submit to guidance and oversight by brother Zac. In his mind I do not think he feels he is the head elder but just another elder along with others in local churches.
If Sreeram reads this post I am sure he can share alot more about CFC Altanta.