People to People is NOT in any way selective. I have a friend whose son was ranked dead last in a high school class of over 400 get "invited" last summer. He was accepted and went (and has now dropped out of high school entirely now that he is back from the trip). They pull invitation lists from ANYPLACE they can get a kids name. We just throw them out when they come.
Which I think is different from the boarding school letter with scholarship information included. Those really are from your talent search results, I think, and I do show those to D.
I am not saying your kid can't have a valuable experience with People to People programs, but they are quite expensive for what you get. I personally think there are lot more valuable summer programs in the US and abroad than this, especially for a gifted kid.