Congrats on your weight loss! I don't know anything about tennis elbow specifically, but I have a lot of other tendonitis-y problems in my arms and hands. My only advice is to talk to your yoga teacher or find a yoga teacher if you are doing videos. I have problems if I have bad form or if I am pushing too hard. Try to back off a little, modify the poses that hurt, and see if it lets up.
I joined weight watchers on May 1, and I am down 6 pounds. I have always been pretty active, but I need some sort of accountability and portion control. I basically did a "couch to half-marathon" program last summer without losing a pound. I wish I could go back to rewarding myself with tacos, but berries will have to do!