There was an invasion in Shard today with a variety of flying eels.

I used a variety of ways to fight these.
The first few waves were easy enough that I could hit them with TM.
I was able to use branch break a few times. It was kind of hit or miss on whether I could even attempt to cast it in town. When I did hit the eel it would fall to the ground long enough to get a hit or two in before taking off again.

Back when I hunted some of the older gryphons, I used to cast HB on them which would tangle them up in the webs and make them fall to the ground.
When I attempted to cast it on the eels this was the result:
A thousand tiny spiders crawl out of their hiding places, but are unable to reach the flying cloud eel.

When I used to cast it on flying gryphons to bring them to the ground it was an older version of the Harawep's Bonds spell. Not so old as the type that poisoned critters, just the pre-3.0 version. Since someone went through the effort to write special spell messaging for the scenario of casting on a flying target, I'm sure it is behaving as designed. Things change and now that I think about it, having spiders somehow get to a flying gryphon is kind of far fetched.

I have no idea if this is possible or something you'd be willing to do, but if you cast HB at a certain level of mana, could jumping spiders be summoned, capable of jumping up to a flying target and webbing them?