Crystalline increase crystal rarity by 37.5% at (5) and floor 500 is +5 Tier Rarity.
I think 500% Crystal Rarity on legend maps or 1000% on eternal maps is similar to Crystalline but I wouldn't say they work like + Tier Rarity. Still, the gains from legend maps are so good at floor 500.
Crystal Rarity % from legend map and Crystalline can also work for crystal dropped from feat and probably the same for converting eternals. Tier rarity comes on what floor you get and crystal rarity is all around.
Edit: I think crystal rarity % probably slightly influences tier rarity in legend/ eternal maps.