Attaches glucose residues to poly(RboP)-wall teichoic acids (WTAs). 4-O-[(D-ribitylphospho)(n)-D-ribitylphospho-(2R)-glycerylphospho]-N-acetyl-beta-D-mannosaminyl-(1->4)-N-acetyl-alpha-D-glucosaminyl di-trans,octa-cis-undecaprenyl diphosphate + n UDP-alpha-D-glucose = 4-O-[(2-beta-D-glucosyl-D-ribitylphospho)(n)-D-ribitylphospho-(2R)-glycerylphospho]-N-acetyl-beta-D-mannosaminyl-(1->4)-N-acetyl-alpha-D-glucosaminyl di-trans,octa-cis-undecaprenyl diphosphate + n H(+) + n UDP Cell wall biogenesis; poly(ribitol phosphate) teichoic acid biosynthesis. Deletion of the gene abolishes all WTA glucose modifications. Belongs to the glycosyltransferase 2 family.