There're several ways to go around this:
1) Make your client and your side be part of the same cluster: https://docs.jboss.org/author/display/ISPN/Getting+Started+Guide+-+Clustered+Cache+in+Java+SE - You can then use cache invocation Flag options to decide what to cache locally (using local only flag) and what to be replicate (without any flags assuming that the cache is configured with a cluster mode other than local)
2) Set up a client/server between the client and your side and viceversa (https://docs.jboss.org/author/display/ISPN/Infinispan+Server+Modules), so that communication can happen both ways. You'd need to consider whether your side can connect to clients...etc
I had some what similar requirement where teh granularity was even fine , were in i did not want all teh fileds to be replicated(only one node needed those extra fields). So i made them transient.
This will work only when oen node is modifying teh cache , and that itself is teh node which requires these transient fields.