It doesn't at the moment, but I'm told it will have in the future, in the meantime we have several WCF message inspector classes that perform actions like validating incoming XML against XML Schema's.
I've set up a .NET Class / Method custom match rule on one of these inspectors, on the 'AfterReceiveRequest' method. One of the parameters has a property called ListenURI which I'm using to split the business transaction.
I have a feeling it's measuring the time it takes to execute that class / method rather than the response time of whole WCF transaction, but it should give you an idea of the load going through each of your WCF endpoints.
Hope that makes sense.