Involved in the synthesis of mannosyl phosphorylinositol ceramide (PubMed:9323360, PubMed:12954640). Catalyzes the addition of mannosyl to phosphorylinositol ceramide. Suppressor of RVS161 mutation (PubMed:9323360, PubMed:12954640). a 1D-myo-inositol-1-phospho-N-[(R)-2-hydroxy-very-long-chain fatty acyl]-(R)-4-hydroxysphingoid base + GDP-alpha-D-mannose = an alpha-D-mannosyl-(1<->6)-1D-myo-inositol-1-phospho-N-[(R)-2-hydroxy-very-long-chain fatty acyl]-(R)-4-hydroxysphingoid base + GDP + H(+) Heterodimer of SUR1 and CSG2. Leads to altered sphingolipid synthesis. Belongs to the glycosyltransferase 32 family.