Gnomes have a lot of alternate racial traits that give out varying SLAs. They all replace the Gnome Magic racial trait. But do they count as it for feats and such?
By the rules, no. Sometimes this is appropriate too. The casual illusionist feat for example probably shouldn't work with fell magic with its necromantic focus. Faerie dragon magic is a reasonable substitute for gnome magic with illusions though IMO.
TL;DR: no, but it'd be a reasonable house rule in some cases.
So ask the GM, ok. Thank you.