Yes, IF your system control panel has a cellular communicator installed and working properly.

Conversely, if your system's cellular connection fails, you can still control the system through its Wi-Fi connection, provided the Wi-Fi is working and connected to the internet.

In either case, the Wi-Fi or cellular connection should be restored as soon as possible to maintain the desired redundancy.  

If you're on the premises, make sure your Wi-Fi router has AC power and that the router itself has a working connection to the internet.

The system control panel must have AC power or be running on its internal backup battery in order for its cellular communicator to work.