Leaving ones bow at camp is always a risk! A lot depends on the amount of time you have to hunt, 5-7 days on an OTC hunt for 2 + guys I'd seriously consider having my bow at all times as opportunities can be rare, as some have mentioned you just never know when an elk may slip in from the side or behind you, I've also had the shooter miss & the bull continued on towards the caller. This being said it is extremely rare for the caller to get the shot, I've called in 100's of bulls over the years in tag team setups & could count on one hand how many shooting opportunities as the caller I could have had. To date I've never killed a bull as the caller where the bull has slipped in on me in a tag team or 3-4 man setup. Yes a few bulls & cows showed but they are generally on high alert & in search mode as they show up looking for the elk they heard. Anything is possible but in most cases is highly improbable from my experience in tag team setups.
Consider your situation & do what's best for the team! (grin)
ElkNut1