Is there a reason to NOT use the same subnets across multiple sites? Including the WLAN Connection?

I have two restaurants, and to make things easier, I'd like the network in the second restaurant to match in both SSIDs and subnets. In my mind it's easier to troubleshoot. Is there anything to consider before I roll that out?

Subnets include
native IP for the firewall
point of sale
audio
VOIP