I'm not sure how it'll change when you get around to applying for uni, but this year there were various medicine courses that didn't mind you taking further maths at AS, but didn't accept it as an A2 subject. If you enjoy maths, and feel like you'd achieve highly in further maths I'd definitely take it for year 12 if you're struggling to find something, or you just really enjoy maths. It's hard to tell how much this'll change over the next 2 years though.