There are three levels of minima:
1) LPV, which must use SBAS (EGNOS) for vertical guidance.
2) LNAV/VNAV can in principle derive its sub-LPV-precision vertical guidance from either BaroVNAV or SBAS (EGNOS). I don't think that the SBAS flavour is yet incorporated into the relevant EASA AMC though. So in practice most such approaches are flown using BaroVNAV
3) LNAV has no proper vertical guidance. However, an SBAS (EGNOS) will display the advisory glideslope as "LNAV+V". But your minima are the same as for the LNAV only non-precision approach, with no "credit" for the glideslope.
Heathrow 27L has LNAV/VNAV minima that are lower than the plain LNAV minima by 120 ft.