My view on finishing the top of the bench is that you want it to look reasonably nice, and also have some resistance to damage, but it's not fine furniture. If your bench is anything like mine, its gonna get dinged, solvents and finishes will get spilled, and dust and clutter will collect..
I inherited my bench from the the previous owner of our first home - that means that Ive had it for 50 years, and I have no idea how long Fred owned it, but when I got it, it was unfinished. Periodically, I use an old chisel to scrape off any glue that has stuck to the top, and then sand it smooth and wipe on a shop-made blend of boiled linseed oil, turpentine, and paste wax.