I'm not sure that I follow exactly what both of you are saying. The point of entry into the building these days, especially in new builds, is often into a cavity or other inacessible location.
That is the point of entry into 'the fabric of the building'.
However, the (I would say only) purpose of main bonding is to prevent people
inside the building touching an extraneous-c-p which, in the absence of bonding, might be at a different potential from that of the electrical installation's 'earth' within the building. For that reason, I would say that the relevant 'point of entry' is where the part enters the interior of the building, regardless of where it enters the fabric of the building.
If a conductive part (externally in contact with actual earth) enters the fabric of the building, but never enters the interior of the building,, then it doesn't need main bonding. That would obviously be silly in the case of a gas or water pipe, but must be common with, say, structural steel.
If one bonds each and every extraneous-c-p within the building, 'as close as practicable' to where it enters the building, then one can be confident that the all of the building's electrical installation (within the building) remains adequately bonded, whereas if the bonding happens outside in the manner being discussed, the adequacy of bonding is at the mercy of any changes to the pipework external to the property - which is why I would personally (in terms of electrical common sense) be more comfortable with each extraneous-c-p being bonded (ideally 'visibly') within the building.
Either of those 2 scenarios will result in an advisory of non conformity during a gas inspection.
'Gas inspections' are, of course, a law unto themselves, particularly since it seems that gas and electrical regulations may sometimes be in conflict. In some senses, I'm a little surprised that gas regulations have not 'banned' the bonding of gas pipes to TN-C-S earths - but, if that had happened, there presumably would have been a major war between the conflicting considerations of the electrical and gas industries
Under both of those situations the closest place for the correct position for the connexion point is prior to the inaccessible location or prior to the T-piece and both of those will be prior to the point of entry of the interior, ie outside. John seems to have agreed with that in post #8 but then contradicted in #10.
No I didn't. In post #8 I wrote (with emphasis added here) that 'outdoor bonding' would be conformant with regs
"... IF it could successfully argued that "in the (external) meter box" was the "nearest practicable point" to where the gas pipe entered the (interior of the) property" ... and then in post #10, I merely re-asserted my belief that (in the context of main bonding) it was the point of entry
into the interior of the premises that was what 'mattered'.
Where is the alleged contradiction?
Kind Regards, John