Do we need to apply a bonding agent to the cinderblock base walls before we apply stucco or veneer?

If you are using reclaimed or painted cinderblocks, it would be required.

If you built your base with brand new cinderblocks, just spray the blocks real well w/ the water hose and get those blocks as clean as possible. Let the blocks dry for a day or two then apply the stucco or veneer directly to the cinderblocks.