I think it's the piano. Knock that stuff off...lol.J/k If military press is O.K. on the elbow, but bench is not, I would assume that your elbow position is not the same during the press. During bench, are you flaring at the bottom of the lift or tucking? You should tuck your elbow at about a 45 degree angle from your body at the bottom of the lift. If you haven't been doing this, try it. Hope it helps. If not, I would say stop doing any lifting that aggravates the elbow until it's healed.
"I can't wait 'til tomorrow, 'cause I get stronger every day!"