My understanding of wormholes is that they bend space to allow two distant points to be close together. We've never seen that subspace does this.
You're thinking of a space fold drive. The term "wormhole," coined by John Wheeler, is by analogy with a hole bored through an apple by a worm, connecting one part of the apple's skin with a distant part on the other side through a tunnel passing through the interior. A wormhole, or Einstein-Rosen bridge, is an analogous structure, a sort of spacetime "tunnel" connecting two parts of spacetime by passing through a higher-dimensional realm.
And again, I am not saying that a beam through subspace is
a wormhole -- any more than John Wheeler was saying that the universe is literally the skin of an apple. It's an analogy. I'm saying they're two different things that have similar effect. They're both ways of sending matter from one part of space to another without passing through the intervening space.