You do NOT want to do hammer curls when you have tennis elbow.
The only type of curl you want to do are ones where the palms are ALWAYS facing up. In fact, this is how you should be lifting and picking up everything in your life for a while. This will help calm the tennis elbow down and help strengthen the underused bicep.
(When you have tennis elbow the lateral forearm gets too strong; the bicep gets too weak. Curling in any fashion with the forearm rotated, ala hammer or reverse, is working the lateral forearm. Don't do this!)