I admit I am not an expert, but having skimmed through Doc 4444 I see nothing that provides other vertical separation minima applicable only to VFR aircraft. Therefore I must assume that the minima you listed apply equally to IFR and to VFR aircraft, and you are correct that lateral separation must be effected if vertical separation does not exist.
However, those minima only apply within that airspace in which VFR aircraft are provided separation services at all. From 188.8.131.52:
Vertical or horizontal separation shall be provided:
a) between all flights in Class A and B airspaces;
b) between IFR flights in Class C, D and E airspaces;
c) between IFR flights and VFR flights in Class C airspace;
d) between IFR flights and special VFR flights; and
e) between special VFR flights, when so prescribed by the appropriate ATS authority;
See also the Note at 184.108.40.206:
Note.— Pursuant to Section 5.2, but subject to certain exceptions stated therein, ATC is required to provide separation between IFR flights in airspace Classes A to E, and between IFR and VFR flights in Classes B and C. ATC is not required to provide separation between VFR flights, except within airspace Class B. Therefore, IFR or VFR flights may constitute essential traffic to IFR traffic, and IFR flights may constitute essential traffic to VFR traffic. However, a VFR flight would not constitute essential traffic to other VFR flights except within Class B airspace.