Yes, you will need to upgrade the SRM system to EHP3.
1951805 - Adjusted Version Interoperability for Business Suite 7i2013
1388258 - Version Interoperability within the SAP Business Suite
You can make use of the UDA tool to confirm this.
As you are upgrading the ERP system to EHP 7 which is based on NetWeaver 7.4 you will need to upgrade the other systems like SRM, BW to a supported release.
Regards
RB