Aluminium boat owners don't like copper.
As long as you don't expose copper directly to the aluminium, I would think it is OK.
Use alumium terminals for all ground connections to aluminium.
They are easier to change than the aluminium channel frame.
"It must not be based on a dissimilar metal. copper is particularly problematic. Side note: Copper pennies, copper shell casings, heavy copper wire used as fish clubs have all been known to be starting points for corrosion if left in the bottom of an aluminum boat."
"When corrosion is at work metal actually leaves the least noble metal in any circuit and deposits itself on the most noble metal. Aluminum is low on the nobility tables so it will give itself up if it is in a salt solution near a more noble metal and there is electrical activity (natural or man made) present. "