Nope. You always need to call for parties of 10 or more. The direct line for dining parties of 10+ is (407) 939-5665 or you can call the regular dining line (407-WDW-DINE) and they will transfer you.
For parties of unusual size (like my Chef Mickey's ressie for 28 people in October), they had me talk to Chef Mickey's directly. That was wonderful, b/c they had ALL the information I'd need. They later emailed me my confirmation #'s and told me I could email them back if I needed anything else pertaining to that night's dinner!
Good luck with your ADR's!