There are patches to enable this, but they have not, as yet, been integrated. In any case, they won't help you to fail over from one server to another.
If/when those patches get integrated, it would be highly useful to support failover between servers. I guess the requirements for this would be:
1. Expose the openssl session cache config, so that distcache can be configured to share the SSL sessions between servers
2. Implement some way of attaching the PEAP/TTLS tunnel state to the session cache, or otherwise be reachable by the other FreeRadius server, so that when resumption occurs the inner info can be (re)used for authorization.
I don't know much about the OpenSSL session API, so the 2nd could be either very hard or trivial ;o)