If the component is stably-named (i.e, it’s a default subobject of the actor and not created at runtime) - then yes you can send RPC’s to/from that component without it needing to be replicated, so long as the parent actor is replicated.
Note that for components, you should do the following in the constructor:
SetIsReplicatedByDefault(true);
Whereas for actors, you should set the property directly:
bReplicates = true;
The reasoning behind it is silly - but it’s a lesser-known evil.