Bestwishes is not a brand of jewelry, but a word to express good wishes, which is generally used in the signature part of English letters, that is, the salute part of Chinese letters. Wish in bestWishes is a noun here, and the plural form is wishes.
Wishes means hope, desire and what you want to do, so the usage of bestwishes is very extensive and common. Generally, there is no identity restriction, and it is generally used among peers.
Therefore, when the words "bestwishes" are engraved on jewelry, it is not a brand, but a very widely used greeting. Giving a friend jewelry with the word bestwishes can express your wishes to the other person.