theres no evidence to say that a lack of
muscle soreness the next day means that you havent worked it well.
having said that I dont know anyone who wouldnt feel the same if they werent sore the next day LOL
theres no reason why your Bis shouldnt be sore.
if it were me, I would change the routine. it could be a case of slightly 'out' form which is very easy to do with biceps. you could be bringing you elbows to far forward, using your shoulders, not contolling the negative ..... it goes on.
I'm sure I saw a post recently by alex(AJ) about bicep form which, if you've not seen, you should search for.
personally I do higher reps for bis, with slow negatives (3-4 seconds to lower the weight) I wouldnt do as many sets as you posted either.
I like to hit Bis after back coz the've already had half a workout then all I'll do is:
1 X seated incline 21s
3X8-12 seated DB curls (slow negatives)
1X triple drop seated
hammer curls.
and that is quite a lot after back but my Bis need that amount.