Yes, Vespertine Garden is definitely a goth band because most of their albums belong to the Darkwave and Second Wave of Gothic Rock genres, which are among the core subgenres of goth music. Albums like Canticles of Love Loss and Agony are examples of their goth sound.
Vespertine Garden is located in United States, Texas, San Antonio, active in 1999 — 2002. You can find more information about Vespertine Garden on their GothDB band page.
Want to check if another band is goth? Search other bands.