All of my dogs went to my home club, and all other clubs I shot at. None of them were allowed in the clubhouse, unless I was there working on a non-shooting day. That being said, I have no problem with a dog on the porch, so long as it is well behaved. My last Lab would come to the line with me during practice, sit, and move to the second post, where she would lie down. She would move to post 3 if asked, but that was it! She would lie down and wait for the shooting to be done. The guys I shot with were all dog people, so they would visit with her when she was beside them, and nobody had a problem with that. During competition, she was either at the truck, or tied behind the trap I was shooting on. My present dog loses focus when asked to sit too long, and will wander off aimlessly, so she is either tied, or in the truck, while shooting is happening.
As others have posted, if food is being prepared, dogs should be kept outside, but if it just a shelter-type of clubhouse, it is up to the club to regulate how they want dogs to be handled.