Skepticism is in order. A better measure might be whether any documented miracles (not "wonders") have occured among non-Christians today. (Although, if so, it would still be by the grace of Christ). Anyway, the only miracles that I am aware of are Christian.
Here's documentation for healing in ancient times:
"Another way of developing a taxonomy of illness would be to study the anatomical ex-votos left at various healing shrines.(83) The body parts represented are few in kind, mainly eyes, ears, hands, feet, genitals, occasionally breasts and rarely internal organs.(84) Yet these objects can provide important clues as to a native taxonomy of illness. Certain shrines, moreover, contain a disproportion of organ-specific anatomical ex-votos, such as eye votives at the Athenian Asklepieion(85) or chest votives at the Amphiareion. This might be explained in several ways. Certain ethnic groups tend to become "ill" in certain areas of the body or to describe their syndrome of symptoms in culturally specific ways, a fact well documented by medical anthropologists.(86)"
From a Notre Dame University website
[I've checked this link prior to posting and it doesn't work. I saved the page to my hd] URL is www.nd.edu/~jneyrey1/miracles.htm I can't take the time to read it all right now but skimmed through it.
Offhand, I can't think of any healings outside of the Christian context, but I'll bet if I dug deeply enough into information from other cultures, I might find evidence or mention a few spectacular healings.
Having a western mindset (me), our God would get all the credit and glory, naturally.
And, naturally, Catholics have the edge on miracles and healings. I know protestants get some healings, too, but they seem to be less dramatic, but no less gratefully received. How do I know? I was a protestant and I've had several lesser healings in my family, also several non healings. When my kids were little I started reading the bible to them and we had warts disappear and a stomach problem corrected. That's just a couple. I personally escaped about three surgeries through what I believe were my prayers and faith, one when I was a child and don't remember asking God for it (it wasn't quite totally complete but my mother was stunned). Other times I wasn't so blessed.