These metals don't really degrade that much. There are loads of stories of apparent 'irresponsible' storage over decades that has resulted in little to no degredation. I guess that's what is so brilliant about these metals for this use case. That and scarcity, becasue other metals are just as corrosion resistant (if not capable of sustaining far harsher conditions).
Store away from heat, moisture, people and animals... Infact, anything that respires, soil, plants etc...
Make sure there are no spaces in these vaccum sealing bags. Never know with these chinesium grade food sealers. Gases trapped might do some damage and not aesthetically as pleasing as atmospheric corrosion when it's trapped in a bubble causing a localised patina. What are the bags made out of? Hopefully nothing leaching from these bags either.
Just as good would be putting them in another inert envionment like under argon or nitrogen. When ever you open your capsules spray a bit of inert gas in there if you have it. This will dissipate any corrosive gases like nitrogen oxides, sulphur oxides, sulphides, oxygen, CO2 etc... Or could put the stuff in a vaccum box.
The surface finish will only last indefinitely in an inert environment. No mint, or dealers blister packs can be assumed properly sealed, or capsules or cases etc... Sometimes patina adds value for people after years and years anyway.
If it's bullion then maybe not worth too much effort of course.