@petecarlton; In answer to your question:
GuitarChat either didn't exist prior to the last Bash or it was in its embryonic state. I have to admit, I only went there once. I have no idea whether it has attracted a sizeable membership by now.
I think it would be a mistake to advertise this as open to guitarists. Not belittling the guitar thing as many of us play that also, more that we should preserve our niche. Otherwise we risk getting over-ridden by well meaning attendees who probably have a lot more events oriented to them specifically than we as bass players have anyway.
Just my thought.