A bond beam is the horizontal counterpart to a block wall’s grouted vertical cores: a course of the wall grouted solid along its length, so that a typical single bond-beam course adds one course-height band of fully grouted wall to the takeoff. It is the piece grout estimates most easily miss, because the NCMA per-area estimating table covers vertical-core grouting only — bond-beam volume is always added separately on top of whatever the table gives for the cores.
The published estimating rates run per lineal foot rather than per wall area. NCMA TEK 4-2A Table 5 rates an 80 lb preblended grout bag at about 2.7 lineal feet of 6-inch bond beam, 2.0 feet of 8-inch, or 1.6 feet of 12-inch — the same ASTM C476 grout that fills the vertical cells, just consumed by the course. On a wall takeoff, that means two additions ride together: the table volume for the reinforced cores at their spacing, plus one lineal-foot line per bond-beam course in the wall.