I contacted (emailed), the Sonesta Travel Pass Customer Services and rewards team, provided screenshots of my IHG Rewards Club - Spire Elite Membership Materials, and received this email from them around 2-3 days later below:
Good afternoon Mr. XXXXXX,
Thank you for contacting Sonesta Travel Pass. We are happy to assist with matching your IHG Spire Elite account status. We are excited to welcome you as a Sonesta Travel Pass Elite member!
You can view all the great benefits by following our link: Sonesta Travel Pass Benefits. If you have any further questions, please contact our Sonesta Travel Pass team by calling 1-855-622-2160 Monday to Friday between 9:00 a.m.-8:30 p.m. (EST) and Saturday-Sunday 9:00 a.m.-5:30 p.m. (EST).
Have a great day!
The Sonesta Travel Pass Team
on June 1, 2020