Corkage
Corkage refers to the fees the convention facilities will charge for the privilege to bring in outside food and alcohol. These fees offset the loss of income to the hotel that standard catering generates. Hotels make a lot of money on catering and restaurants and will tend to object to your serving food and drink to your members that you do not purchase from them. Corkage is may be charged both in function space and on other spaces as well. Naturally, corkage policies vary with every establishment and with local laws as well.
Corkage waivers and other legalities
Obviously the expense of hotel catering is prohibitive for parties that are run and paid for by individuals or small groups. For this reason most conventions negotiate a corkage waiver with the hotel. Here the hotel agrees to allow self-catered parties. These parties are often required to be in specific areas so as not to disturb other guests.
You might need to point out that you are not selling this food as it is being given freely to members of the convention. You need to secure a corkage waiver in your contract, if possible, that your Green Room, Consuites, and individual Room Parties will not be subject to these fees. You may not legally need to get a corkage waiver for Room Parties since those are not being hosted by the convention, but you may still want to for the protection of your members.
Consuites that serve beer are also in competition with hotel restaurants or bars that serve alcohol. Also, hotels might get uncomfortable because the way alcohol is served or distributed within the hotel could threaten their own Liquor License if it is not done properly. Reassure the hotel that you know the legal ramifications and that
a) You are not selling alcohol
b) Only your Staff will serve alcohol and those people will all be legally of age to do so
c) Your staff will check IDs and obey liquor laws including the ones about not serving minors. You will also encourage private individuals who are party hosts to follow these laws.
d) You know what the liquor laws are in your area (don't lie-- know this)
e) You will inform all members including those hosting parties that alcoholic drinks are not to be carried down to the levels of the hotel where their liquor license is in effect
f) Ops will help resolve any issue regarding the above
In some jurisdictions, places that sell alcohol are required to have official bartenders serve it. Your hotel may try to insist that you hire their bartenders to serve alcohol in your consuites. Refer them to point a.
Please note that laws vary. This is not legal advice, this is contract negotiation advice. If you are uncertain as to your legal position, consult a lawyer.