I am arriving at Shanghai Pudong Airport on China Eastern from Chongqing at T1.

According to the process on the official website, you don’t need to collect your baggage at PVG. It will be sent to the last destination and you just need to follow these steps:
Arrival – Confirm Onward Boarding Pass – Check in – Quarantine – Immigration – Security Check – International Concourse – Boarding
Generally speaking, you can get the seat reservation and VIP lounge pass in Chongqing directly. You can confirm with your airline company which airport you will get your seat reservation and VIP lounge pass.