From a safety viewpoint all ground points are equal.
For _RF_ however, one ground point _may_ be better then another,
depending on how the wiring goes through the house, and where the ground
wire is picking up QRM, hence Richard's suggestion to feed the receiver
from a wall outlet in another room.
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Even better: If no AC is required but say 12 -14 V-DC , run the receiver
from a sealed lead-acid battery and only have a RF earth.

My complete station runs on 12V batteries (charged by 2 solar panels and
a wind gen) ,resulting in NO mains born interference .

If charging from mains ,one could switch-off charging while receiving
and only put charger on battery or batteries while transmitting.
however when the batteries are on the charger all the time the batteries
will probably 'absorb' any mains noise ; moreover the mains power supply
unit then does not need to supply peak current to the transmitter ,just
the average current which for a typical 100 W PEP transmitter (even with
compression) is not more than approx. 8 Amperes.
In such a situation the station will also always be available (for some
time) during a power outage ......emergency comms.

With batteries the supply voltage will on average be below 13.8 V ,hence
the transmitter output will be slightly lower resulting in a signal
which will be lower but never more than a small fraction of 1 S-point.

Note : When reducing power by a factor 2 the resulting signal will be
reduced by half 1 S-point.

Frank GM0CSZ / KN6WH