As said above the first thing to do is to check with the hotel. Haven't stayed at the Crowne Plaza but most hotel shuttles are aware of the inbound flight times and usually will be waiting a requisite amount of time for pax to clear customs between loops. Since you have a pretty good sized group perhaps the hotel would be accommodating and try to make sure you're checked onto the shuttle before leaving.

One other thing is to make sure you're carrying newer, crisp US currency. For some reason the locals are a bit suspicious of grimy bills.