This article examines Facebook conversations between members of a transnational social network of US- and Mexico-born English/Spanish bilinguals. Extending Bourdieu's theory of language and symbolic power, the article uses the framework of language ideologies to explore how members establish identity and membership differently depending on whether they communicate primarily in Spanish or English. I argue that they use commonly held ideologies of language as tools to contest identities and establish membership. For example, US-born English-dominant members use Spanish to index language ideologies of standardization, correctness, and separation with other English-dominant members to bolster Mexicanness. However, when faced with Spanish-dominant and Mexico-born members, English-dominant members use an ideology of language elitism to position their English-Spanish bilingualism as more highly valued within their transnational network. The findings of this study also reveal that Facebook is an empowering space where bilingualism is the linguistic capital necessary for full membership in their transnational community.