For leveling purposes, I agree with luxv: use Tav. Tacos for pulling (boost in CHR as well as DEF). I personally would avoid the Opo-Opo Crown since a Tav. Taco gives you better stat bonuses, AND frees up the head slot for something else. However, as with gear, your foods will change depending on what role you take.
If you cure a lot (perhaps at lower levels, where there is a lot more time in between pulls), using +MP food might be better for your party. It's very rare that bards will ever have to rest for MP, but it can happen with lower level parties (e.g. you help backup cure and need to rest while the melees take down the current mob).
You can start meriting as early as 60+, but your role will generally be the second bard (in which case +MP food again might be better). On the other hand, if you are pulling for a merit party, I recommend using Tav. Tacos until you get better gear and can reliably land elegy and lullabies with just gear. No one likes a puller who cannot stage mobs (i.e. land lullaby). A fully-merited bard with good gear will not require foods (of course no one will stop you if you do).
PS2: Hades / BRD75
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