[Antennas] Antenna separation?

[Hylton Conacher (ZR1HPC)]

Hi,

I currently have a 2m slimjim up on top of a pole and would like to also
add a 70cm dipole and HF vertical (Diamond BB7V) to the same pole.

How far apart must the antenna be from each other ie must the 70cm
slimjim be mounted 2m away up/down the pole?
Likewise Must the 2m slimjim be 2m awaay from the HF vertical?
Unfortunately I can't have the HF vertical 160m away from the 2m antenna
but that is a degradation I'll live with.

When the antennae have to be a certain distance apart, does this relate
to the antenna feedpoints or the outer edges of the bands antenna?

73 de ZR1HPC
Hylton