Their web page refers to 'Sunday 12 November', which means that the page hasn't been updated since 2006!
http://www.jersey.co.uk/thelounge/
Given that there are no links at all from that page, and that you report that the phone number is unobtainable, it seems that The Lounge has long gone.
Also, searching for The Lounge's address brings up links showing that the actual name of the business which traded from there (as 'The Lounge') was 'Cafe Arts and Crafts Jersey 2000 Ltd', which then became 'Crush Juice Bars Ltd' before being dissolved in December 2008.
Chris