Well.....i knew i was doing something silly but followed recipe from somehwere and had exploding bottles
So after 48hrs DO NOT bottle with crown caps but only with screw caps bottle (as adviced in good books like Roger Phillips's). You will need to check for excessive fermentation after 5-6 days and after that.
It is a delicious drink though!!!!! and yes natural yeasts are doing a pretty good job here!
Update on the Elderflower Champagne