I am going to assume that these are both point to point T-1’s and the end points of each circuit are in the same location. If that assumption is correct, then yes you can bond them together. This is typically done through a PPP multilink connection. You probably have everything you need if these T-1’s are sitting in the same router on both sides. You would simply configure a multilink interface on your router using the “interface Multilink1” command if this is a Cisco router. Then, within the interface you would have to specify the encapsulation(PPP) and identify the group number. Each serial interface would then have to reference the multilink group number. If you are familiar with port-channel setups on switches, then this is somewhat similar.