Well someone likely told you the wrong information:
*Restaurant Depot is wholesale only. To qualify for a free membership account, on your first visit you need to show a valid reseller's permit (business license) or tax-exempt certificate (for a non-profit organization) and show proof that you are authorized to purchase for said business or organization.
Nothing in there about being a food related business, if you have a reseller's permit you should be good to go.
Fill out that form online, then go to your local store to pick up your membership card.