For UCSB do you need the 3.2 GPA for tag by the end of fall or do you need it when you submit the TAG application?
it depends by UC. Look at http://admission.universityofcalifornia.edu/counselors/files/tag-matrix.pdf which is for the current year (eg. students wanting to enroll in Fall 2016). For that admission cycle UCSB says you need a 3.2 by the end of Fall 2015 which is the semester when you would have applied for entry in Fall 2016 .
If you are applying for entry in Fall 2017 then push the dates forward a year.
This is my interpretation; it wouldn’t hurt to call or email UCSB admissions to confirm before you change your life because of something you read on the internet.