Multi Plant BOM Setup - 8.04

We currently have two plants. Our Vantage rep told us when we had her
onsite that we need our assemby part number to have seperate BOM
revisions for each plant (example being A and JA). The revision A
assmebly will use revision A subassamblies. The revision JA assembly
will use revision JA subassemblies. I am creating the different
revision levels in Part Maintenance. After I check out the rev A BOM,
how do I select the proper revision A components in the Engineering
Workbench? BOM structure (without operations) would be:
Plant A
001-0001.asm, Rev. A
.002-0002.asm, Rev. A
..003-0003.prt, Rev. A

Plant JA
001-0001.asm, Rev. JA
.002-0002.asm, Rev. JA
..003-0003.prt, Rev. JA