Where is it mentioned the Accelerator's Vector Transformation works on all 11 dimensions?
In To Aru Majutsu no Index light novel volume 6, page 57, it is explained how teleporters use the 11th dimension to move objects:


  [...] Though the phrase “to teleport within space” sounded simple, the theory behind it was to get away from the three dimensions, find her position in the eleventh dimension, and then calculate the vectors to teleport. [...] 


In volume 20, page 107, it is specifically explained that:


  When he reflected teleportation powers, a strange phenomenon occurred in the 3
  dimensional world, [...]