Yes. For a new office, the petition must show the financial ability of the U.S. entity, or the foreign entity, to start operations and remunerate the manager. Capital contributed by either partner to the venture is evidence of that ability, provided the venture's own records show it.
Capacity to pay is about the venture's books
The new-office rule asks for evidence of the size of the U.S. investment and the financial ability of the foreign entity to remunerate the beneficiary and to commence doing business in the United States. In a joint venture, the U.S.
entity's bank statements showing both partners' contributions, the capital-contribution schedule in the operating agreement, and the Harrison Hot Springs company's own financial statements together answer that. The American partner's contribution does not create any problem for the immigration analysis; the issue it does raise is control, which is answered by the governance documents rather than by the money. Budget separately for the immigration fees: the Form I-129 fee, any premium-processing charge and employer-side surcharges that depend on the petitioner's size and composition, all set out in the USCIS fee schedule, Form G-1055.
Fit-out, equipment and staffing costs for the spa are business expenses and are not required evidence beyond showing the venture can operate.