Is the following sentence natural for native speakers of Mandarin?
這件衣服綴飾了許多亮片,適合在晚宴上穿著。
Is "綴飾" used naturally? I thought it's supposed to be used as a noun.
Yes it is a natural usage. In fact, I would even say that 綴飾 as a noun is derivative of its verbal usage, considering that it is a compound of two verbs. An analogous case could be 收藏, which is both a verb meaning "to collect", as well as a noun meaning "collection (that which is collected)".
綴飾 can either be used as a verb as "decorate", or a noun as "decoration". For the given sentence, 這件衣服綴飾了許多亮片 - This cloth is/has decorated with many paillettes. Here, 綴 means 縫補(sew) or 連結(connect), both are verbs.
EXample for 綴飾 used as a noun:
缀饰是点缀装饰的意思。
這件衣服綴飾了許多亮片,
This outfit is decorated with hundreds of sequins,
適合在晚宴上穿著。
(it is) suitable for wearing to an evening reception.
连衣裙上缀满了数以千计的闪光装饰片。
(The) frocks were stitched full with thousands of sparkling sequins.
(“sequin” was apparently originally the name of a gold coin of the Venetian Republic, also the name of a Turkish gold coin. Women of the Levant apparently wore them as decoration, earrings or necklaces)