As far as I know (and this is what my recruiter said just a few days ago when I talked to him), the sequence is OCS, commissioning, TBS, API, then flight school, and possibly IOC between TBS and API. You are not required to have time in-cockpit to become a SNA with the Corps.
However, I believe there is a program for PLC-air contractees to take flying lessons their senior year of college at a civilian airfield on the government's dime. I don't know many details on this, however.