Perfect bound.
At the spine all the bleed will be ground off, additionally the glue will prevent you opening the pages completely flat so even if the folding is out by a millimeter or 2 you'll never see it.
I'd set the document up as spreads. The printer won't mind if the bleed for the single pages comes from the opposite page.
The only binding I can think of that truly needs bleed in the spine is ring binding.
... there was the puzzle of why the sun came out during the day, instead of at night when the light would come in useful.
Terry Pratchet