According to Polygon, you will be able to carry your saved progress back and forth between the PS3 and Vita versions of FFX and FFX-2 HD. It has also been confirmed that the two games will ship on one disc on the PS3, but will be individual purchases on the Vita.
Final Fantasy 10/10-2 HD Remaster Will Support Cross-Save
According to Polygon, you will be able to carry your saved progress back and forth between the PS3 and Vita versions of FFX and FFX-2 HD. It has also been confirmed that the two games will ship on one disc on the PS3, but will be individual purchases on the Vita.