Thanks for suggestions. With a bit of trial and error, I came up with sed one-liner which escapes all of the glob pattern characters. Not pretty and not sure if it is 100% complete but it did successfully exclude all of the problematic files for me.
rclone sync -v --exclude-from <(sed 's/[.\*^$()+?{|]/\\&/g;s/[][]/\\&/g' exclude.txt) ....