Don't breath in time with the bellows!
I found that I had to learn not to when I started accompanying myself singing, having been learning to play for some months.
I would think that's less critical if you're not playing an Anglo. On my duet I change bellows direction at the logical phrasing points, where I would breathe if I were singing (but perhaps more often). I don't see why I shouldn't breathe with the phrases even if I am not singing. I've never noticed if I actually do.
David, I think at least one of us has misunderstood Robin. Taking a breath at the change-bellows-direction points -- or vice versa -- may be a useful technique for singers, but I understood Robin to mean breathing in when you pull the bellows and out when you push (or vice versa). This seems to be a natural tendency that many beginners (I was one) need to overcome, and it's very difficult to sing while breathing in.
My personal advice for uncoupling breathing from bellows movement is:
...1) Practice singing an extended single note, while frequently and deliberately reversing bellows direction in playing a tune against your "drone".
...2) Practice playing an extended single note, while frequently and deliberately (more often than necessary) taking breaths as you sing a song against it.
...3) While doing 1 or 2, throw in a breath without a corresponding bellows change or a bellows change without a corresponding breath. Then throw in a couple.
...4) Continue adding unmatched changes as in 3 until you work your way up to complete independence of breathing and bellows. Now you can start matching your breathing to the phrasing of the song and your bellows reversals to the phrasing of the music and demands of your instrument (i.e., how long you can play without running out of air, or reversals required by the notes on an anglo), while keeping the two independent, except as those separate requirements happen to coincide.