The SNES VC releases basically have 3 files:
The ROM is basically the original file itself. It can be played in a PC emulator but it won't have any music since the sound is split into a PCM file. The other file is the VAR file which basically makes any changes to the original rom. One example is on F-ZERO, the VAR file modifiers the game so the screen doesn't flash black every time you hit a wall.
Some of the VC releases like Donkey Kong Country do have the original rom in there as well (aka the .smc / .sfc file) and actually play fine on a PC emulator. However they just take up more Wii blocks and can actually be deleted and repacked.
Later VC releases do use a compression (LZH8) on the ROM & PCM files but a tool has been made to uncompress them.
Looking at Romancing SaGa 2, the .VAR file is 2 KB. The stuff you have listed, I would have thought the file would be bigger. The .ROM uncompressed is 2MB. I'm going to compare it to the original.
With this tool, it is possible to extract the file from the WAD into a working .smc file. https://github.com/Plombo/vcromclaim