Actually, holy symbol specifically does *not* fall under the spell component thing, unless your DM is willing to house rule it. Spell Component Pouch is specifically listed in the phb, and holy symbol is listed separately. In the description of Spell Component Pouch, divine focuses (like holy symbols, and mistletoe) are specifically excluded. There is no room for ambiguous interpretation here. If you allow a wooden holy symbol, you are in house rule territory. There are plenty of spells that don't require divine focus, so your cleric/druid can get by. And the bard can learn to sing. No instrument needed for that. The fighter doesn't get martial weapons, so the other classes can make do with less as well. If you don't like it, then why are you taking Vow of Poverty?
The "magic vestments" spell is more debatable, although I would say that the duration quickly makes the "magical clothing" effect "effectively permanent" if you have multiple copies of this spell, and thus I would personally not allow it. But I will allow this one to be a judgement call, as it is not clearly spelled out what the status of spells temporarily enhancing clothing would be.
*However*, I just noticed that the "Magic Vestments" spell requires a Divine Focus, which the vow of poverty character is specifically not allowed to have as it is not on the "allowed" list (maybe the writers of BoED specifically thought of this case and didn't put divine focuses on the "Allowed" list for this reason). So "Magic Vestments" is disallowed for this reason, even if you don't disallow it for making "magic clothes".