I won so random trash [ended]

Staff calculates if the package itself would count as bundled. So if a base game goes on sale for 95% off, but that discount for the base game wouldn't bring the package down below 95%, then the package remains unbundled.

On the other hand, if the deluxe version gets bundled, it's normal for the base game to get bundled as well, since you could always list the deluxe version as the base game otherwise [due to SG's policy of "you can always provide extra content beyond what you list"].

For example, it's normal for some of the RPGMaker games on SG to reach below bundled threshold with their deluxe versions, but not their base versions; in the past both versions of the game have become bundle-listed at such times.

Generally, the only time you should see a deluxe version bundled but not the base game as well, would be if the DLCs had gone cheap enough to drag the deluxe version down below bundling on their own weight alone.