Regular un-coated copper can be useful to repel slugs and snails but too much copper can be harmful for plants. The plastic coated wire should be okay if you remember to check that the coating is intact/undamaged.
Love your idea. Please tell me where you found the owl bead. I have a friend who collects owls and she would love that. I also make sun catchers using copper wire and beads but do not attach them to plants. I attached them to stakes (re-purposed chop sticks
) and stick into the soil of hanging pots - keeping the copper away from the vegetation.