If you use a RoundRobinPolicy it should work.
In opposite to http requests, which are not load balanced, the ejb proxy will have this LB feature.
What you need to do is instead of jnp://host.1099 you need to use jnp://host:1100 to have a JNDI-HA context.
If you lookup the EJB you need to keep that proxy and invoke methods with this proxy. In that case both server will be used