It all depends on the subjob you want to use. If the sub job is going to use MP then pick Tarutaru as they get the most MP. If you want your Bard to live longer and have a melee subjob then pick Hume or Elvaan. All three of those races have the same CHA rating. Mithra or Galka have lower CHA, but its still possible to play as one, with the help of +CHA gear. Galka Bards live allot longer for BCNM fights where they need to use AE Sleep. Tarutaru Bards die quickly in those fights.
Most bards pick White mage or Red mage as a sub because it helps the party and you have little time to be meleeing the monster.
Look! Stats of level 70 Bards!
Tarutaru:
70 Brd/ 35 Whm
HP MP STR DEX VIT AGI INT MND CHR
869 184 53 59 57 56 72 61 70
70 Brd/ 35 Mnk
HP MP STR DEX VIT AGI INT MND CHR
1000 0 54 63 61 55 70 57 68
Hume:
70 Brd/ 35 Whm
HP MP STR DEX VIT AGI INT MND CHR
1080 130 61 59 61 52 60 65 70
70 Brd/ 35 Mnk
HP MP STR DEX VIT AGI INT MND CHR
1211 0 62 63 65 51 58 61 68
Elvaan:
70 Brd/ 35 Whm
HP MP STR DEX VIT AGI INT MND CHR
1191 112 69 55 65 44 52 73 70
70 Brd/ 35 Mnk
HP MP STR DEX VIT AGI INT MND CHR
1322 0 70 59 69 43 50 69 68
Galka
HP MP STR DEX VIT AGI INT MND CHR
1463 0 66 63 77 47 54 61 60