Catalyzes the polymerization of lipoteichoic acid (LTA) polyglycerol phosphate, a reaction that presumably uses phosphatidylglycerol (PG) as substrate. Cell wall biogenesis; lipoteichoic acid biosynthesis. The secretion into the extracellular medium is dependent on SecA and Ffh. Proteolytically cleaved. Restores staphylococcal growth after ltaS depletion. Belongs to the LTA synthase family.