I have had a similar issue with a couple of flights I took at the end of April (SYD-MEL-SYD). One posted within two days and the other flight has yet to post.

I completed the missing miles from partner airlines on the web site as you did. I got a response from BA telling me that the claim was rejected as the miles and tier points had already posted

So I gave a call to the exec club and they told me that they have had issues with the system thinking the miles and points have posted when in fact they have not and they would put my claim in the virtual pile with all the others.

So it maybe worth your while to give them a call if they do not post soon.

Just reviewed my account and they have posted this morning