Current transformer (CT) and potential transformer (PT) grounding

Question

There is several documents say that for three-phase instrument transformers (CT,PT), there should be only one grounding point. With this argument, can I short the the secondary sides of current transformer and voltage transformer together on a bus-bar and then ground this bus-bar to create a single grounding point?

In fact, these CT and PT have already been installed at the substation and they are grounded, just not at the same point. My company will install a meter that uses their outputs. This meter have its CT and PT neutral wires connected on the circuit board and as mentioned, these neutral wires are grounded at their own points. So technically, the grounds of the said CT & PT are connected together. I'm asking if there is any potential danger to this.

Note that these CT and PT are used in measurement of High Voltage substation (110 kV).

Circuit to illustrate the idea:

Answer 1

The CT and PT secondary are grounded following the high voltage standards on the high voltage side of the installation. This area inaccessible by uncertified personnel, this grounding may not be removed.

With this argument, can I short the the secondary sides of current transformer and voltage transformer together on a bus-bar and then ground this bus-bar to create a single grounding point?

You cannot, since you would make a ground loop.
If your meter requires this, you must add additional isolation transformers.

Answer 2

so far as I can see.

The grounding of those windings must be at their neutrals else connecting the meter could cause a short-circuit

The two separate ground points must be bonded together else external fault currents could flow through the meter