Anyone know anything about a " Gathering License" ? in delaware

Sounds shady to me. A Gathering License is issued to a not-for-profit group that wishes to sell alcohol to a gathering of persons for one day. Under the regulations, "gathering" means a banquet, picnic, bazaar, fair, or similar private gathering, or similar public gathering, where food or drink are sold, served, or dispensed by non-profit organizations such as churches, colleges, universities, volunteer fire companies, political parties, or other similar non-profit groups having a common civic, social, educational, or religious purpose, or where entrance tickets are sold or entrance fees are required by those non-profit organizations. So either you'd have to have an entrance fee payable to the nonprofit for the wedding, or the drinks would have to be sold, served, or dispensed by the nonprofit. I'm assuming you're not charging to get into your wedding. Is the nonprofit really going to send someone over to serve drinks? And if they did, wouldn't that get in the way of your plan just to use certified bartenders?

See i thought it was weird too but from what i heard through them is we would make a donation to them an they provide the gathering license to us using their name and take the donation to benefit the nonprofit organization.

I reached out to the Delaware ABC,

As a catering company we have ran into the same issue.

As per the Delaware ABC.
They stated that if your event is being held on a for profit venue.

No mater if its sold or brought in, the location, licensed Del catering company, or a non profit will need to get a gathering license.