Trailer hook, yes, always. Trailers depend on the water clarity and water conditions. Cold, muddy or stained water a plastic grub, white, black or chartreuse, match your skirt color, will present a bigger profile, push more water and slows your bait down. Lets the bass see and hear and feel your spinnerbait especially if you are using a Colorado blade. Which is what you want with those water conditions.
For clear or slightly stained water, no plastic trailer. You want to move the spinnerbait quickly so the fish don’t get a good look at it, use willow leaf or double willow leaf blades so you can burn the spinnerbait, but use a trailer hook.