Occam,
I can't pretend to be an expert on this one. But, it seems the LTA rules that were bent apply to domestic duty postings, and perhaps some overseas non-mission postings (I'm making up a new lingo here. I know). That's to say, if you went to Afghanistan or to a UN mission in the Middle East, having the spouse come meet you in London is okay. If you're posted to Fort Bragg for nine months, having your spouse come meet you in NYC is not okay.