[Aerich]

There is generally at least two of every spell (maybe the lvl 8 and 9 spells excepted), although often the second is found in HoW.

Spell access is why role delineation is so critical with more than two arcane casters. What functions do you see each character performing in the party? If you aren't going to send your bard into melee combat on a regular basis (which I wouldn't recommend), then don't give it spells that are most effective if used by a melee mage (e.g. Vampiric Touch, Color Spray, Cone of Cold, Blur, Stoneskin, Tenser's)

I see your party as having two mages potentially quite capable at melee or range, and one buffer/backup caster. Because the F/M/T will gain mage levels so slowly, I'd be inclined to make it primarily a ranged terror instead of a melee fighter, but that's just me. You and only you decides how you play. IMO, The bard is best used as a caster of buffs that are not specific to itself. I would include summons in that category, but spread them around a little (look for summons that gain power or numbers based on the caster's level, like Summon Shadow and the Shadow monster spells). The bard also has an "emergency" function, such that it should have a damage spell or two that can turn the tide of a fight - I'm thinking specifically of Chromatic Orb and Acid Arrow here.

Of the four spells you mentioned, the bard should NOT have tensors and stoneskin - save those for your melee mages. Generally speaking, I'd give the bard party-buff spells only, with maybe one damage spell per level (two at most). The buff spells should be ones that can be cast on others - e.g. Strength, Protection from Normal Missiles, Emotion: Hope; not self-buff spells like Stoneskin.

The bard should learn damage spells with a purpose other than just causing damage: e.g. Chromatic Orb for stunning, Magic Missile for bringing down enemy Mirror Images or disruption, Acid Arrow for disruption, maybe Icelance. Mordenkainen's Force Missiles are an exception and should be taken by the bard because the spell is severely level-dependent and will be much more effective cast by a fast-levelling bard instead of a F/M/T. All casters should have Mirror Image, even the bard, as it is potentially the best (and most cost-effective) self-protection spell and is well-suited to emergency situations (e.g. party's tactical formation is dispersed and bard is targeted).