General Description: XNF files written by FPGA Express (1.x, 2.0.x) will always use angle brackets when defining buses (i.e. BUS<3>). There is no way to alter this functionality.
Under Synthesis->Options->Project, there is a field to alter the "XNF Bus style". However, this field refers only to incoming XNF files read by Express. This is necessary to allow Express to re-assemble buses.
Xilinx recommends treating XNF modules as black boxes instead of reading these files in for re-optimization, as re-optimization has shown to cause problems for some designs. See (Xilinx Solution 3508) for more details.
Any modification of bus naming conventions within files produced by Express must be done manually. Using your favorite text editor, globally search for and replace the angle brackets, "<" and ">".