It might just be me but ESO Plus is not free. Therefore the Furnishing Vault is not "available for free". It's simply included with ESO Plus. It's a paid feature. Please consider changing the text.
the price of the item in the store is 0 crowns therefore Free.
it's the same for other ESO Plus rewards like the statuettes and paintings, these items all make it very clear you need Plus for it.
with the yellow text "Exclusive offer for ESO Plus members"
picture of the Shadowfen Mirescape painting in the store as an example.
miaow! i'm Luna ( she/her ).
🌸*throws cherry blossom on you*🌸 "Eagles advance, traveler! And may the Green watch and keep you."
🦬🦌🐰 PlayStation and PC EU.
LunaLolaBlossom on psn.
LunaFloraBlossom on pc.
It's free for ESO+ members as opposite to ESO+ members getting a discount on some crown items. Where I live I often see ads like "this thing is free with purchase of that thing". No one think that "this thing" is free.