Ubuntu for Android enables the user to connect his mobile to a Ubuntu powered PC, and have one OS access all your data, files whilst maintaining functionality. I.e., when you connect your phone to the desktop, you'll have Ubuntu running on both the devices, and tasks like making calls, sending messages, they can all be done through the desktop environment. At the same time, all the data that you've stored on your mobile device, can now be accessed by the PC, so if you want to tweak some files, or edit documents etc, you can do it on the desktop environment and the changes will be reflected in real time. There would be no need to sync the device to the desktop and waste time. The same applies for the converse as well, if you create a document or spreadsheet( just examples, could be anything), the phone will automatically, have those documents, so when you're on the move, all the things that you need will always be with you.
Now, when one is talking about the Ubuntu Phone, to a large extent, one is talking about the new Ubuntu Touch OS. Ubuntu Touch should be out next month with the stable release of 13.10, but the beta release is already out and you can check it out if you have a supported device. Ubuntu Touch would eventually be shipped sometime next year by manufacturers and one would be using it on everyday phones, just like it is with Android. In very plain and simple terms, Ubuntu Phone/Touch is a new operating system, developed by Canonical which would soon hit the market.
The major difference between the two is that while Ubuntu for Phone provides a platform for having a common OS on 2 devices when they're connected to each other to facilitate easy sharing of data, the other, Ubuntu Phone is the next big OS to hit the market.