Bundling is crazy since a good IP (Internet) connection allows using any of of hundreds of phone services, usually at very attractive prices.
For retail customers, cable phone requires a separate modem and often some kind of connection to internal phone wiring, complicated and difficult to do. No business would go through this charade, their phones are always IP direct.
IP telephone sets (plugged in to a wireless or wired router or switch) are available, for just a little more than a good analog phone, but cable companies act like that is exotic tech for huge companies.
If possible (and your Internet is solid -- which it may not be with TW), dump your old phones, and use IP phones instead. Unbundle!