I have used SoBo glue for clay to clay and clay to wood bonds. I don't know if you can see the fisherman figurine in my shop banner if not you can see it here on Flickr. For the base I used a 1/4" piece of plywood. Liberally coated it with Sobo glue and when it was tacky / dry I lay my clay over the top, rolled it into place and baked. The entire plywood is covered with brown clay. That figurine was made back in 2004 and there has been no problem with either the clay or the Sobo. The other great thing about Sobo is that I have used it for raw clay to raw clay and baked clay to raw clay connections. It is also heat tolerant. So I have been able to use it and still bake again in the oven. According to the bottle its 'for use on porous and semi-porous surfaces like paper, wood ceramics, ribbons dried or silk flowers, beads, chenille, leather and feathers. It dries clear, flexible and permanent and won't yellow'
http://www.flickr.com/photos/judithlynnoriginals/5628050070/Hope that helps.