Webbing/cord and bolts
I always learned that bolts and any kind of webbing or cord is a no-go. Even if the edges are not sharp the webbing/cord is bent around a very small radius which weakens it significantly.
Today there is one new option: Kevlar cords. These can be used directly in bolts, as they are very abrasion resistant. So if you have any with you, this would be the ideal solution.
In your specific case with thick webbing twice through the bolt this problem is somewhat smaller, still I wouldn't do it. My goto mountaineering book has one solution to your problem, which is admittedly looking weird but it works.
You need a biner and a stopper. You pull back the "nut" of the stopper so that you can pull the protruding wire loop through the bolt. Behind the bolt you clip the biner into this wire loop and arrange it such that the long side (opposite of gate) lies flat on the bolt. Now you can use the other end of the stopper as your attachment point (as you normally would with a stopper). The biner is in a similar function as when using with an tuber in guide mode. A stopper is used for its steel cable which is not prone to abrasion/weakening over the edge of the bolt.
K. Winkler, H. P. Brehm, J. Haltmeier, *Bergsport Sommer. Technik, Taktik, Sicherheit (SAC-Verlag, 2. Auflage, 2008), p. 228.
The simple answer is again: This is a no-go. Always use a fixed central point or at least stopper knots. There may be a lot of friction in your particular setup, maybe even enough when fully loaded. Still this is a bad idea, as it removes the redundancy. If one of your two points breaks (unlikely but possible), then there will be a static fall into the second (in your case braked by friction, but still). Especially now as you also have webbing over a thin edge, this would be too much risk factors for my liking. If it is a anchor you walk to on top then you will probably never attach to it directly so there is always the rope between the climber/belayer and the relay which is an elastic element. So there wont be a static fall. Still you will have an unnecessarily bigger force.
A fixed central point does not have this fallacy and the potentially unequal load is really not an issue. One bolt is strong enough, the second one is just redundancy for the very seldom special case (badly placed anchor, ...).