Freediving apnea training is based on two things: increasing lung volume (by increasing flexibility in the chest area, yoga helps) and training the body's ability to use the O2 in the air (done with apnea training and cardio). Both, but esp. the second thing, will help a lot.
If you do yoga for your freediving, that will improve your bodily awareness and teach you better breath control, so that'll help too.
I do both SCUBA and freediving. I love freediving, mostly for the freedom of it. But I've experienced great benefits to my air consumption by training freediving. Some of the benefits come from the things mentioned above, some from the fact that a lot of freediving training (pool or open water) has to do with moving gracefully and efficiently under water. Also, it will really improve your comfort level under water.
So in my book, yes, freediving will benefit your air consumption. Not just the apnea, though, although that does do some.
See ya down there!