Co Location...
I've just left the RAF (within the last few days....) and have had to deal with the issue of having a partner in the service and the associated problems of co-location for many years. Indeed, it is one of the primary reasons for my leaving. My wife is in the same branch and this helped enormously as lots of contact with the desk officer helped to ensure that, at the very least, we were within commutable distance of each other for the last three tours. We were lucky in this repect as we were both aware when we married that it was going to be an issue but we we both knew that the needs of the service come first. The problem would have become a lot more acute if one of us were promoted as the opportunity for co-location or postings within a commutable distance would have become much more difficult.
The long and the short of the issue is simply that if you are married in the services you cannot be gauranteed to be co-located and that has to be accepted from the start. If you are lucky enough to be posted close by as we were (Lossie & Leuchars, Brize & Odiham, Northolt & STC) then take it as a lucky bonus but don't get too used to it.....