Yes, the existing relationship could be reused. There are 2 options:
1. Use NetApp open replication
NetApp OCUM server is not involved during replication.
As of SP8, the support only SnapVault relationship(XDP) is supported. SnapMirror(DP) support will come in SP9.
2. OCUM based replication
An additional setting needs to be configured to import existing relationship.
Please escalate the case so that we can review and configure appropriate solution.