The answer is yes, you can send a neck-tie here and for a fee they'll make it into a bowtie. But is it worth the fee? The good news is, somebody has figured out a less drastic way of turning a necktie into a bowtie:
My assessment, by the way, is that this makes a fairly thick bowtie (depending on the material of the original tie), but overall is seems to work and looks pretty good. It was also reasonably secure around my neck, though I only tested it for about 10 minutes. I may try it out some time soon for my actual day tie.
My pic (quick low-res shot from a webcam):
Like I said, a bit thick, but now bad. Also, here is a link to a diagram, and a second video which is arguably more helpful (though it's via facebook) for doing this.