Are you perhaps talking about bonded (i.e. not bounded) T1? Do you want to bundle these T1's into one channel?
You can use PPP over FR, and configure Multilink PPP to bundle the Frame Relay lines together. On each site, both Frame Relay lines (or PVCs) have to be terminated at the same router. This would be a configuration example for one endpoint:
In this configuration, two Frame Relay PVCs identifies by DLCIs 101 and 303 are being terminated at a single router. It does not matter whether they are terminated on a single Serial interface of if several Serial interfaces are used. Each of these DLCIs is configured to be a container for a PPP session. Corresponding Virtual-Template interfaces that hold template configuration for the respective PPP session are simply configured with PPP multilink, and all IP-related configuration is perfomed on the Multilink1 interface that is the terminating interface of the bundled PPP session.
It is necessary to activate Frame Relay traffic shaping on the Frame Relay interface to support Multilink PPP.