Consider the following situation.
- Both the teacher and her student are not at school when the following occurs.
- The teacher posted a picture of a cake in her facebook wall.
- The student posted a comment saying おいしそう！明日学校に持って来ていただけませんか。
In my understanding, 「～持って来て～」must be replaced with 「～持って行って～」 because the teacher will do the job for the speaker (student) in a direction away from the place where the speaker (student) exists at the time of speaking.
However, according to the teacher 「～持って来て～」is also acceptable because the student will be at the school when the teacher brings the cake to the school.
Which reference is used to determine whether to use てくる or ていく? The location where the speaker exists at time of speaking or the location where the speakers exists at the time the て action will happen in the future?