Not required. Only one of the two members needs be a paid member to communicate to and fro. Let us explain with a simple example.

Example:

If Ramesh (Premium Member) send a personalized message to Priyanka (Free Member), Priyanka will be able to respond with a personalized message since Ramesh is already a premium member.

The same applies to chat. If Ramesh is a premium member, he can send a chat request and Priyanka (Free Member) can respond since Ramesh (one of the members communicating) is already a paid member.