The acid might attack the aluminium, but the resulting salts may help the tannins to coagulate. If you're following that up with base and extraction into NPS, the aluminium shouldn't be too much of an issue, except that resulting aluminium hydroxide particles might contribute to formation of emulsions (but only might).
Thick aluminium pans erode only fairly slowly in the presence of food acids, but caustic base will attack aluminium much more rapidly, along with the evolution of much hydrogen gas. It's definitely important to avoid using aluminium in the base phase!