Catalysis of the reaction: ethanolamine phosphate + Man-alpha-(1,2)-Man-alpha-(1,2)-Man-alpha-(1,6)-R = Man-alpha-(1,2)-Man-alpha-6-P-EtN-(1,2)-Man-alpha-(1,6)-R; R is Man-alpha(1,4)-GlcNH2-inositol-PO4-lipid. This reaction is the transfer of ethanolamine phosphate to C6 of second mannose in the GPI lipid precursor CP2.