OK, this tank is where printing takes place. That's clearer to me now.
Most silicones are PDMS, up to rare exceptions. But families exist depending on the solvent, the catalyst. Usually, all adhere to glass. Was the glass clean enough? My transparent silicone (I believe it was DC93500) adhered to glass and silica easily.
Remove bubbles from a film of viscous liquid like silicone by using vacuum.
Gluing a film without bubbles is difficult and needs essentially practice. You can check how it's done for strain gauges. It involves laying the film at one corner first, then pressing with a finger as soon as you establish gradually the contact. A cloth around the finger tip helps, or fabric gloves. A needle can punch bubbles if you application tolerates than. I did it for a satellite: several people are better than one, and 1h practice is an absolute minimum. You configuration, in a concave location, makes it more difficult. I'd prefer to cover separately each glass plate before assembling them, if possible.
Could an unmoulding spray replace the FEP film?
Do you really want a silicone liner that adheres to glass, and a FEP film on top? To unmould the printed part, maybe you could disassemble the transparent tank (glass, PMMA, PC...) and then the silicone liner is easily removed from the printed part without any FEP.