dtgreene: Yes, but in the Famicom version of FF3, the Bard is so useless it may as well not exist.
Also, that bard in FF4 is not useful unless you are playing the DS version or one of the versions based on it. (One tip: the Bardsong augment is best given to Rydia (makes her far more useful), and while I'm here, the Bless augment should be given to Cecil (makes the middle portion of the second playthrough much more fun).)
PookaMustard: Well, he asked for playing as a bard. So I bet that useful or useless is not much of a concern to him as is whether you can play as one.
Might disagree with Bardsong + Rydia. Rydia has black magic and summons at her disposal, so if anything, I feel like summoning these great monsters and using whatever the most powerful black magic spell available to her (Flare?) is a better idea. Unless Bardsong has a great effect on Rydia.
That said, yep, Bless might work on Cecil, though I remember his active augment slots were full and Bless wasn't one of them.
With respect for Bardsong Rydia, it is actually a very good setup. First of all, there are times when black magic and summons aren't useful, like against enemies that have nasty counters to magical attacks. (The final boss is an example of this.) This means that Rydia normally becomes useless while Bardsong can be used to heal or haste the party.
Healing is important, because Rosa is very busy and sometimes you don't have enough time for her to heal and cast spells like protect/haste, even with Dualcast. The only other healing abilities Rydia gets late game are Asura (which is unreliable) and Whyt (which makes you lose control of her and was removed in the later 3D ports). Hence, having another character who can heal can be quite useful.
Another thing is that some of the bard songs cause status ailments, and the success rate of those is based on Intelligence. (This applies even to White Magic; hence why Rosa's Hold doesn't work that well.) This can be very useful in the Sylph Cave, where Silence is useful against some of the annoying enemies that keep casting spells, and Rydia's Bardsong is the most reliable way to inflict Silence at that point in the game. Also, when fighting multiple enemies, the sleep song works better than multi-targeting the sleep spell.
Then there is Hastemarch, which speeds up the party ATB to the point where the bottleneck is the time it takes for you to enter the command. The best way to use that song is to berserk your physical attackers to reduce the time it takes to enter their commands to zero; hence, you don't want to give it to a frontline character. (Unlike in FF5, I am pretty sure that Berserking a singer will end the song.) You don't want Rosa using it, because she needs to cast Berserk. Therefore, Rydia is the best character to use that song, which makes certain boss fights (including the final battle) much easier. (The only time I would avoid this strategy is against enemies that counter physical attacks or do nasty things if other enemies are dead, but those aren't as common as counters to magic attacks.)
Another thing: You are giving Fast Talker to Rydia, right? Turns out that that particular augment will also speed up your Bardsongs. (Tellah gets Bluff and Twincast augments, since those are more useful on him than on your final party.)
As for Bless, I am thinking of making the second playthrough more fun. By the time you get Bless on the first playthrough, you have Rosa with her Pray ability and aren't going to lose her, so you don't need Bless's ability to restore MP; just have Rosa Pray instead. On the other hand, there is the middle portion of the game when you don't have Rosa and hence normally need to be careful with your MP. With Cecil having Bless, you don't need to worry about that anymore.
Consider that, in the Magnetic cave, you can now do the following:
1. Have Cecil and Tellah use Twincast. There goes your enemies!
2. Have Cecil use Bless to get your MP back. It doesn't take that long.
3. Nuke even more enemies with more Twincast.
For more fun, give Tellah a Soma Drop. Notice that spell with that 99 MP cost? The one you can't cast because Tellah has only 90 MP? You can now use it as much as you want! I think it's worth giving up 10 MP from your final party in order to make the middle portion of the game (normally the worst part of the game) so much more fun.
(Side note: The original version of the game and other SFC/SNES versions have a bug that allows you to underflow Tellah's MP and use the 99 MP spell as much as you want in those versions. Don't know whether the bug is in FF4 EasyType (which is not the same as FF2 US).)