I have only done minimal testing of phone call recording, but it does appear to work.
However, this is only pseudo phone call recording. You need to turn the speaker on during the phone call, and then TapeMachine will record both your voice and what comes out of the speaker. It's a workaround, but it does seem to work, although it may cause echo and poor quality.
To my knowledge, it is not currently technically feasible to provide in/out call recording without using the speaker. There's an Android issue about this:
Issue 2117 - android - Enhancement: Call Recorder - Project Hosting on Google Code