Las Vegas Hotel Reservations Question

[CrushinFelt]

Making reservations for March, there will likely be 4 (maybe 5) people in one room at the Bellagio. Is there any reason I should put more than 2 guests on the reservation (I'm assuming they charge you more for more guests)? Do they actually pay attn to that stuff? I mean, it might be obvious if I put 1 guest and I demand a room with 2 queens and ask for 4 keycards when I get there, but how will they know if I have 4 guests instead of 2?