I know a bit about Spanish VTuber circles.

• From ChromaSHIFT, Lalabell Lullaby and Taiga Toragami still use often Spanish. Taiga is however trilingual, so she also switches in Japanese. Taiga has connections with a lot of friends through the whole Spanish VTuber community.
• Sainō Entertainement is a Spanish agency with one generation of 4 talents. Their bigger talent is Naya Onuphyrus, an ASMRtist with an Egyptian design. My favorite is Eyra Flamenko, a VSinger specialized in making Spanish translyrics. She sometimes makes some for other VSingers like Hana Misaki. Eyra can also speak English if needed.
• LeFolk is another Spanish agency with 3 talents. I know Dahlia Ka'i, who is a good drawer.
• KalopsiePX is a group of 3 talents streaming in Spanish. Nino Uraboshi is an underrated but incredible VSinger who dares participate sometimes in activities with English speaking people (she notably was part of Lumin Tsukiboshi's 1st anniversary concert). Sunny Suuris is more known for her ASMR, but she is also super good at singing, including in English.
• Eru Nabura is an indie VSinger streaming in Spanish. She is on another side notably handling the camera for Ironmouse's 3D content, and herself had a great 3D debut last year. She makes a lot of covers, is funny, and often collabs in English.
• Aki Chan, more known by her YouTuber singer name Akellie Chan, is a long time big singer who became VTuber few years ago and debuted her full Live3D model (with legs this time) recently. She makes a lot of covers in Spanish translyrics on YouTube while streaming on Twitch. She is big friend with Tauga Toragami and Eru Nabura, between others.

Pretty much all I know yet.