Dredging up an old thread just because I have seen a pattern in my CX flights crediting to BA. They always get processed on a Tuesday or a Friday. I feel that the details take two days to get to BA, and then they will credit on a Tuesday or Friday - whichever comes first.
For example, flights taken on a Wednesday or Thursday always get credited on the next Tuesday. Flights taken on Sunday, are credited on the next Friday.
Looking at flights over the last couple of months I also get Friday or Tuesday postings now. If i fly on a Monday or a Thursday it seems to be luck of the draw whether it posts a day later or 4 days later. For example I took a Monday morning 0905 flight to Tokyo and points were posted Tuesday, but the week before I was on the 0900 to Singapore and got nothing until Friday.