If you're going to make the bag from sil nylon then the only thing that will stick to it is silicone. If you use a pu coated fabric there are probably many more options. There are also fabrics out there that "weld" together with an iron, not sure how you'd get that to work with your valve, but for the rest of the bag you wouldn't have stitching holes to worry about. There used to be a youtube vid. with some guys making stuff sacks with the heat weld material and an iron but I can't find it right now.
is a link to some fabric.
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Deep peace of the running wave to you.
Deep peace of the flowing air to you.
Deep peace of the quiet earth to you.
Deep peace of the shining stars to you.
Deep peace without end to you.
adapted from - ancient gaelic runes