If I had to guess, neither of the above tapes will work with sil because the tapes are not silicone based. At least as far as I know cuben is not silicone coated or impreg. neither is your average spinnaker fabric.
Go to pg 57 in this pdf for a silicone based tape.
I'm sure you could just bond sil together with silicone rtv and sew through it after it dried.