I have a BOG lunch reservation for my trip in October (I was unable to get dinner even at 180 days out). My question is are the dining rooms first come first serve? In other words, can you choose which dining room to eat in in advance, somehow?
For breakfast and lunch, BOG is seat-yourself. So if you find an open table in any room, you can sit there 
That’s right. Going there in April, my first choice was the room with the rose and thunder, followed by the main ballroom. After experiencing that, and finding it too noisy, I think I’d rather opt for the third room, and go for a walkabout to take photos of the “popular” rooms.