Internal pages with external database

Hello,
i have on website on wp for travel agency. I have one page with listing of hotels, and each hotel have detail page with photos and descriptions.
I use rewrite plugin and make each hotel with seo frendly url.
Hotels is in external database, not in wp db. I make custom template page
hotel.php in themes folder and make query to external db and display information for each hotel.
all work normally for visitors, but not for google indexing. hotels pages not indexing. How-to can set this pages for indexing from google-bot ?