The way to import Enpass into Bitwarden (via its Web vault) is to export the Enpass vault as a .json file. Bitwarden understands Enpass’ Categories, as Types, and will import Enpass’ Tags as matching named Folders. Enpass entries associated with multiple Tags, Bitwarden only recognizes the first, left-hand, tag.
Be aware, Bitwarden handles each .json file as a completely new set of information so importing a second, updated .json file, will create duplicate folders and entries. It will not update the existing entries.
Alignment of data is generally accurate, but Bitwarden occasionally misaligns login usernames and e-mail addresses, if the two are different.
I can only speak of Bitwarden Web vault and Windows desktop app, I don’t use the mobile apps. Also, I currently use the free version of Bitwarden so, while attachments, within an Enpass .json file, are simply ignored, I can’t say whether they would correctly import into a Bitwarden paid account. Keep in mind, Enpass’ attachments could total more than Bitwarden’s 1 GB limit.