This study investigated Spanish articulatory patterns in bilingual speakers through a comparative analysis with English, focusing on isolated vowels while controlling for vocal tract differences. A recently developed, wearable electromagnetic articulography device was used to track tongue and lip motion. The y and z-coordinates were used to classify 5 Spanish vowels. The vowel classification results showed medium to high accuracy. While small positional differences indicated distinct articulatory configurations, the overall size of the vowel articulatory distinctiveness space was comparable between the two languages. The similarly high classification accuracy and similar vowel distribution patterns suggest the feasibility of training Silent Speech Interfaces in both Spanish and English for bilingual speakers. To our knowledge, this is the first study on vowel kinematic distinctiveness in Spanish.