A "V" is a three-person relationship in which one person -- the "hinge" -- has romantic relationships with two other people. The two other people -- the "arms" -- just have a platonic relationship with each other (either as friends or as acquaintances).
In this case, GalaGirl is describing you as an "arm person," your wife as a "hinge person," and some person your wife will meet in the future as the other "arm person." This is hypothetical, of course, since your wife has not met any such person yet.
Hope that clears up the confusion. There is a glossary thread at:
http://www.polyamory.com/forum/showt...5365#post15365
Hope you and your wife get things worked out; be sure to let any third person you meet know what your situation and intentions are.
Regards,
Kevin T.