Hide glue, Hide glue, Hide glue.
I've seen several posts in this and other forums suggesting the use of modern glues such as TBII, TBIII, Urac, Cyanoacrylate and others for sinew and horn applications. I don't understand why. In my experience, it is more difficult to find the horn or the sinew than it is the hide glue. Hide glue is simple to use and it is god awful strong.
I have sinew bows that I made almost 20 years ago. They still shoot, very well. In fact, one of them is still my favorite deer hunting bow and has been used every year since I made it. No failures, no repairs, no tuneups. I've done a bit of sinewing with hide glue as of late. The little woman doesn't even know that I'm doing it. It doesn't smell much at all. The horn, on the other hand smells pretty bad when sanding or cutting it.
Hide glue, Hide glue, Hide glue!