Yes, you have the option to download purchased designs from the design service and use them on VistaCreate.
At this time, it is not possible to download free VistaPrint designs for use in VistaCreate.

Note: Designs downloaded from VistaPrint cannot be edited once they have been re-uploaded to VistaCreate. To make changes, you must edit the main file in VistaPrint and then re-upload it to VistaCreate.