You will not be surprised to learn that I disagree with most of the people who believe BA should open the doors of its lounges to anyone’s retinue of bag carriers.
BA already has a very generous guest policy for Silver and Golds (and oneworld partner airlines’ Elite status passengers); that is clear and unequivocal – one guest per passenger, no ifs, and or buts. Its lounges remain of a consistently high quality, and are rightly seen as the jewel in the crown of the BA offering.
That makes it simple for passengers to understand, and simple for lounge staff to enforce. The expectations of others are also managed, and it goes some way to preserving the exclusivity of what remains a premium offering.
Having a more generous policy might seem fine as it suits your pupose for that once a year trip with the family – but what about that family with more than one child, which holidays every two months, should they be permitted access? People travelling with elderly parents? Teams of sportspeople? Nannies? Maiden aunts? Those travelling from smaller outstation lounges where space is a premium, or a delay means the sanctuary of the lounge is a welcome respite from a crowded terminal?
“Putting a note in the booking” to permit lounge access for children is not something which should happen, and there I think is a flaw as I rather think that was a callcentre agent fobbing you off with something which is not within their power – or the system’s power – to deliver.
As we have seen in the thread on US First Class tickets not permitting lounge access even on paid F fares, BAEC’s lounge access policy, where a Gold card holder can get access to the BA First lounge for both themselves and a guest even when flying on a deep discount economy ticket is extraordinarily generous, especially when you realise the range of food, drink and other perks on offer.
It is quite clearly against the rules to permit more than one additional guest to a BA premium lounge.
There is already a simple way to gain lounge access for those travelling with you.
Pay for it.
This can be done either using your miles in advance or with cash on the day/through Manage My Booking, booking you into a cabin which permits such access.
An alternative would be to have your travelling companion earn BAEC status themselves – easily earned with just one exEUR trip to NYC aboard Club World London City), and if you are truly valuable/loyal to BA, that should be easily accomplished within your annual travel planning.
Alternatives include the Priority Pass lounge access scheme (though not very useful at T5, admittedly) or to go and sit in one of the many restaurants within T5 and set up camp there.
The status quo has worked well for decades, and is already very generous. There is no justification for changing it.