This KB Article refers specifically to iTunes
Q: I've submitted my podcast for approval to iTunes, how long will it take?
A: Apple have no service level agreement on approving or rejecting podcasts. In our experience it can take upto 14 days for your podcast to be reviewed and/or approved/rejected. You will receive an email either way from Apple with the outcome so if you've been waiting more then 14 days please check your spam filters etc.