Getting your villas close to one another is a request the person you rent from will have to make when they make your reservation (altho on check-in you can ask for changes)...they may have to call to do so; not sure that kind of a request can be done via online booking...when you check in, if you're not close together, you can ask for one or both of your parties to be moved so that you are close together...depending on what villas are available on your check-in day, the front desk folks may be able to do that for you...
In my experience, when I bring guests (in a different villa) Disney always seems to put us "together" (next door or across the hall or something like that), whether I ask for it or not, when I make the reservations at the same time...in fact, they do so even if it means not granting a request I did make (e.g., I REALLY like ground floor...more than once, they've put me on a higher floor, next to my guests, on the theory that I'd rather be next to my guests)...if you tell your owner to tell MS when they make the reservations that the occupants of the two villas are traveling together, there's a good chance they'll place you close-ish ...
But it's no more than a request...no guarantees...