On the BA information page under additional allowances for Frequent Flyers
it says Exec Club Gold and Silver and One World Emerald and Sapphire
are permitted an additional free checked bag in any class of travel for
the cardholder and any customer travelling on same booking (excludes
hand baggage only fares)

This appears in the BA information today 29th Sep 2014. I thought
that sometime last year the extra baggage allowance was restricted
to just the actual card holder and not extended to passengers on same booking.

Secondly there is I believe now confusion with One World. On the One World
site it seems to say that the extra bag is now only offered to Emerald
One World and not to Sapphire.

I recently travelled on BA and showed my Sapphire card to add a second
bag. This caused a variety of hassle. Firstly I was told that my card
did not entitle me to the second bag allowance. After escalating I was told
it did but only if my One World number was in the booking (rather than
my BAEC number). I wanted to earn avios and tier points with BA not on my
Cathay One World card. As a solution I suggested that they put my One World Cathay card in the booking which apparently would allow my baggage
limit to be shown with a two bag allowance and once the bag was accepted
to change my FF number back to BAEC but was told they were unable to do
that.

I have never had a problem with other One World airlines in changing either
say from an AAdvantage to BAEC number at check in and if they could put the Cathay number in why could they not change back to BA. Should I actually have even needed the One World number in the booking I am sure
I have checked in an extra bag on AA just by showing my One World Sapphire ? I think some airlines have space for a second FF number for these
situations but not BA ?

I even thought about just logging in to Royal Jordanian or Finnair etc
and changing the FF number back myself but not sure what counts the number in the booking or the number on a boarding pass.

Has anyone had similar experiences or know what the definitive rules are ?