One way to tell if the firmware update is applied is to look at the size of the download. (Note I am only talking here about the public seed, not the developer one.)
If you got 472MB, you got the delta or patch without the firmware update.
If you got 741.7MB, you got the combo without the firmware update.
If you got 519MB, you got the delta or patch with firmware update.
If you got 788MB, you got the combo with firmware update.
It is however hard to use this method to determine if you got the delta or patch because those file sizes are almost the same (only 6 bytes difference).
Here are all file sizes for this build.
FirmwareUpdate.pkg (46.7 MB)
OSXUpd10.10.2PublicSeed.pkg (delta) (472 MB)
OSXUpd10.10.2PublicSeedPatch.pkg (patch) (472 MB)
OSXUpdCombo10.10.2PublicSeed.pkg (combo) (741.7 MB)
Also, if you were able to get the links using the methods I described before and replace the filenames for the delta or combo with FirmwareUpdate.pkg, this gives the direct link for the firmware update.