Answer: If the writer merely meant "add a 5 and a 9" that would be kind of silly - there's no need to indicate adding a 5, ever, and if you add a 9 it's assumed that the chord would have a seventh. A "+5" really means "augmented 5." And if this writer also included "+9" then he presumably means an augmented ninth. That would be the only rational excuse for including 5 and 9 in the name when "7" is already there. That suggests that the notes of this chord are, in triadic order, Bb, D, F#, Ab, C#. Which is not a bad chord. I voiced it Bb, Ab, D, F#, C# and liked it: