Does Toll-Free voice and messaging need to be with the same provider?

No, Toll-Free voice and messaging do not need to be with the same provider. You can have a different voice provider than your messaging provider on a TFN.  

Sinch can provide both the voice and SMS/MMS services if you wish, as we have telephony services for TFNs. However, with Sinch you can choose to enable just SMS/MMS messaging, just voice, or both.

Learn more about Toll-Free Numbers from Sinch.