A very simple line of reasoning from the Bible can give us a very clear look as to the abundant authority for this to happen in the church building or with funds taken from the "church treasury".
Let's make that journey through the NT together...
"And they continued steadfastly in the apostles' doctrine and fellowship, in the breaking of bread, and in prayers." (Acts 2:42, NKJV)
Notice that word, "eating". If Acts 2:42 is a command by example, and I believe that it is, then we are commanded to fellowship with one another. If fellowship can be done by eating, and it can, then the fellowship meal conducted at the building of the local congregation is something which members of the Lord's church know very well, an expedient. That is to say, it is something which is lawfully done in order to carry out a command which was not specifically identified to be done in one way or another. An example of this would be the worship of the saints at a specified location, often owned by the church in that area, known as a church building. Since we are commanded to worship in Spirit and in Truth (John 4:24) and that worship is to be a gathering of Christians for edification (Hebrews 10:2-26) then the building is the expedient to worship. The same can be said with regard to the fellowship meal. Since fellowship is commanded (Ephesians 3:9) and there is Biblical example of the early Christians doing so through a common meal (Acts 2:42, 46) then it is just as expedient to do so within the building in order to carry out that command as it is the one to worship.
This question may have never been asked of you but if it ever is, the answer is written clearly in your Bible.