Thanks for the gross receipts definition. But my question is really about whether Texas property is attributable to CA.

Accordingly to FTB instructions,

the LLCs are subject to an annual fee based on their total income "from all sources derived from or attributable to California" (R&TC Section17942). Total income for LLC fee purposes is "gross income, as defined in R&TC Section 24271, plus the cost of goods sold, paid, or incurredin connection with the trade or business of the taxpayer."