is there a way to tie all the same voltage sources together in Altium?
Right now if I use the voltage source symbol it will indicate that there are 2 separate voltage sources and there will not be any need to connect them together in the Altium PCB View.
The two individual "VCC_VD_3V3" power nets are automatically tied together since they are on the same sheet and have the same net name. You do not need a net-tie for this scenario. If you are looking to tie another net with a different name to the VCC_VD_3V3 net, then that would require a net-tie type component.
For multiple schematic sheet projects, the "Net Identifier Scope" selection in your project options will dictate how the power ports will be tied together between sheets. See the section "Defining Net Connectivity" (and below) for more info on that. https://techdocs.altium.com/display/ADOH/Connectivity+and+Multi-Sheet+Design