Modern cell phones are small computers, sharing much of the same software (e.g. Android phones run on the Linux kernel), so I feel they should be treated no different than a regular computer, with the exception that they more commonly have multiple network interfaces such as WiFi and mobile network.
If a computer is compromised, an attacker can certainly use that access to attack whatever network the computer is connected to, regardless of the medium.
Also, the other answers discuss how a compromised phone could allow the network's WiFi PSK to be used by the attacker. This isn't very useful for a remotely compromised phone. Also, this will require root access, while a malicious app has enough privilege to launch attacks on your network.