One caution is that Hyatt doesn't have nearly as many properties as the other chains and they also tend to be more expensive. If your travel plans were more stable, that might not be a risk, but if you're not sure where you'll be sent and if there will be "budget constraints", what will you do if Hyatt's not an option?

Any of the three major programs (PC, Hilton, Marriott) can be a good backup plan. PC might be best, as you can maintain top status by holding the credit card. Hilton will also give you mid-level status from the right credit card. Any of those programs can be optimized to deliver a ton of value from points, as well.