Where do people level alt jobs now?

[Iscah]

Get yourself a Squadron Battle Manual. Add the FC exp buff to it...

Don't the squadron manuals all override FC buffs with the same effect?

[Evergrey]

Don't the squadron manuals all override FC buffs with the same effect?

"Grand Company-issue literature outlining basic combat techniques.

Increases EXP earned by defeating enemies in the field.
EXP Bonus: +15% Duration: 120m
Overwrites company actions with similar effects. "

Indeed it does.
I do however believe that, if I remember correctly, food buffs still works.
It's slim, like 3% or so. But hey, it's at least something.

Raisins is a cheap food one can get from NPCs.
I tend to stock up on them each expansion for my leveling journey.