You "make" a loop but "take" a bight, as unhelpful as that may be. A loop is a step in making a knot, where as a bight is just a handful of rope somewhere in the middle of it.

You can tie a regular bowline, or a bowline on a bight. The same knot will need a different technique for tying on a bight, since you can't pass the ends through. When you tie a bowline on a bight, first you take a bight, then you make a loop.