Dimensional Bolt is very good for its specific purpose, which is to provide a way for the summoner to create a surface to place a summon on. If you place that surface off to the side, it won't interfere with existing surfaces.
Elemental totems being worse than blood ones sounds more like a problem with elemental damage totems than with Dimensional Bolt. Bolt is a magical attack, so it scaling off of INT is fine. Especially because it is intentionally not best used as a direct damage attack.
Bolt has a non-intuitive and narrow use-case, but that doesn't make it a good ability.
In combat, for actually hitting an enemy, it is unreliable and weak.
In combat, for getting a side-surface, 2 AP is over-costed for a random and tiny surface.
In my opinion, Bolt is not good even for the narrow purpose of making surfaces. Wands, grenades, elemental arrows, and other surface-creating abilities are good for creating surfaces, because they actually give you the surface you want and do something strong and useful at the same time.
Bolt is good for stunning your party and totems when it randomly creates a stun surface just large enough to connect with your blood pools.
Bolt is good for healing the zombies you're fighting when it picks poison.
Bolt is good when you want to create a small amount of damage on a target and a surface that may be too small to even fit a Totem/Incarnate into.
So unless bolt is your only surface-creating ability and you spam it before combat until it finally picks the pool you need, then it's a hard pass.
This would be a bigger use-case if Blood wasn't the only good surface to create on at the moment and Flesh Sacrifice wasn't already the best racial and better for that purpose.
The Int scaling is fine, except that Bolt is the only Int ability Summoning has, so it may just not be relevant to the user a lot of the time.
