I was there. It was part of the South Bank Centre in London's annual Meltdown festival, where a figure from the music world gets to curate the centre's programme for a couple of weeks. In the year in question the curator was John Peel, and one of his evenings was Spiritualised with SY opening. SY then joined Spiritualised for an improvised (I assume) encore.
I missed the encore because Spiritualised bored me and I went home
Tracks 8-10 on the bootleg are taken from a BBC radio broadcast of part of SY's set. Two other tracks - French Tickler and Hits of Sunshine - were also broadcast.