I don't have a ton of experience with creating a Bundle in sandbox and then installing it in production. If all of the fields from the SB bundle already exist in production, is there any inherent risk of the production data being overwritten? For further context, all that I bundled from SB was a workflow, which then included all of the related fields into the bundle. As far as I know, all of the fields that are used in SB are either already used in production or were created in advance of this. I've created the bundle and just am having cold feet with installing it.

Following thread because I'm also curious.

For a workflow, likely no, unless the field type changed for some reason on sandbox. That would require you deploying the custom field, and not including it in your mainfest.xml though.