Posting this from a practice bot game right now.

As venomancer with 5 HP, running towards the newly-spawned Regeneration rune, Tiny runs over to it and scoops it up despite being at full health and missing only a little mana. I was then killed by the person chasing me.

It seems bots have no priority over who gets the runes, only who is closest to them when they spawn.

Also, bots seem to run to where the rune is going to spawn before it actually spawns, as well, with 100% accuracy over which side of the river it's on.. That might need to be fixed.