Originally Posted by
englisha
Just to put some closure on this thread and to explain what happened :
I called LATAM and gave the new PNR. Initially I was told that it wasn't ticketed, but I then gave the representative the 125 ticket numbers. It took some time, but I believe he manually added these numbers to the PNR and now I can see the booking on latam's website. So all worked out well in the end.
I think that's a very useful bit of intel; knowing the failure mode appears to be that LATAM haven't linked the (external) ticket number to their internal booking reference makes it much easier to prompt with the 125- (or, I assume, 001- or other OneWorld) ticket number to cause them to sort it out.