Also, how long would it be before this spell wears off, and what would happen if I tried to get someone else to reverse it? Not to bind her to me, but just to bring back things to normal?
ANSWER: This is a difficult question and as I see it there are two separate parts. The first is whether magic of this type exists and whether it can do what you ask it can. The second part is whether in this instance magic has worked this way.
As a general answer, yes, magic can be this powerful but the focus and and effort it would take to maintain would suggest it was unlikely to be magic undertaken either lightly, for trivial reasons or by the unpractised. In my opinion anyone capable of generating an illusion as potent as being able to deceive a person as to which country they are living in is unlikely to be doing it for relationship gain. Again, in my opinion, this kind of magic would suggest the practitioner is spiritually developed and therefore unlikely to use magic for such trivial personal gain as the common love spell. So I believe it is unlikely your wife is under this kind of spell and I believe it more likely she has fallen under an infatuation of a particularly charismatic individual. Don't underestimate this, the power of desperate love can rival the most powerful magics. I do not believe she is in a similar mental state to a zombie or acting against her own will. I think she is acting in what she believes is her will but a will borne out of the delusion of her infatuation.
But to answer all the questions you pose, let's assume this is a spell. The time it takes to wear off will depend on the continual efforts being put into the spell, if the effort is continuous then the effects may very well continue indefinitely. But few people are able to extend this kind of effort long term so chances are the spell will have a limited shelf life. Your patience will likely be rewarded if you wait for events to run their course.
In honesty counter magic may work but if this is magic then whoever is doing it sounds quite knowledgable and I doubt a reversal spell will do much to stop them.
In this situation I advise you to do nothing. Either your wife is genuinely infatuated and will not thank you for your involvement until her infatuation has dissipated or she is under the power of a magician and intervention on your part could be harmful and even dangerous to yourself.
If you do get evidence and I mean proper evidence that she is under a spell I would suggest the magic you employ is of the harmonious and balance restorative type rather than combatative against the man she is with. But fundamentally as I do not believe she is acting against her will, I do not believe this is a situation in which magic should be employed.
Image http://www.sxc.hu/photo/596376 (Dlritter)