...If you're playing the blues in A then I would have thought you would be bending the D up towards the E rather than the Eb

Dunno C-flat ... just going by what my ears tell me. I copy-cat a lot by playing along, trying to match pitch-for-pitch, and I notice that in a lot of the runs I'm copying, it sounds to me like the guitarist starts from the flatted fifth and bends up to the fifth, a 'modest' bend, admittedly. In my moderate approach do I seldom start from a whole step below and bend up a whole step, realizing that it's not uncommon to do that. I just don't seem to hear it on the record that way.

Not a blues run, but because of its 'isolation' in the passage and its almost universal familiarity, it makes it easy to hear an example I cite to back up my personal experience: the first note of Jimmy Page's solo in the 'fast part' of Stairway To Heaven. (Page did give a nod - in more ways than one - on occasion, to the blues.)

From his post, FrankHam cites the b5 as being contained within the blues scale. I've gleaned from a few readings that the pentatonic minor scale only contains five notes, excluding the octave: (In the key of A) A;C;D;E;G (in other words: 1;b3;4;5;b7).

Another scale that I've seen referred to as the 'blues' scale, or the 'pentatonic blues' scale, adds a b5 to the mix. I wasn't aware that the maj2 and the maj7 intervals were considered part of any 'blues' scale.