List your committee membership, list the roles you performed as a member: one may be acquisition, you've been the 'primary point of contact for several sponsors', you have probably negotiated, (co)signed or drafted sponsorship agreements with these parties... etc.
I have performed a similar role for a student association. Whenever this was brought up in job interviews, they wanted to know what I did, what I learned doing it and what challenges I overcame. Don't name names unless asked. The companies you're interviewing with probably do not hire new graduates for their professional network, and the people you've worked with (at your sponsors) are not usually the real movers and shakers. Plus, the good reputation of your sponsors is not your accomplishment, you may come across as a show-off.
If 'experience dealing with a certain type of company' is relevant to the positions you are applying for (jobs in purchasing, acquisition or sales), you might say: 'a large accountancy/IT firm' or 'several multinationals in finance and insurance' or 'several local businesses'. It gives the interviewer something to ask about (if they do care) and shows that you can be discrete.