Scroll through their clients list and you won't find Mark Driscoll these days. However ...
as recently as May 9, 2014 it looks like Mark Driscoll WAS listed as a client for Yates & Yates.
Furthermore the first printing of Mark and Grace Driscoll's Real Marriage mentioned that it was published in association with Yates & Yates , LLP.
and in the "ring the bell" category of posts.
Ah, yes, see Warren Throckmorton's comment asking a few questions. Whether or not Yates & Yates opts to answer Throckmorton's questions on record or publicly remains to be seen. What can be verified by way of The WayBack Machine (at least for now) is that Mark Driscoll was listed as a client up through early May 2014.