I am now in chapter 6 and have defeated Bohdi..but the problem is that even though i have a romance wif Viciona(i spoke to her 17 times already), bohdi did not bite her and make her into a vampire...is there a problem wif these or is my romance wif viconia not deep enough??
You haven't progressed enough. I think you need at least the double of your current romance talks before Bodhi will bite her. Try pausing the game more often, this will trigger romance talks.