The Trellis docs instruct to git clone the bedrock repo.
The Bedrock docs refer to
Is there a practical difference between these installation steps for bedrock?
The only difference I’m aware of is that running the Composer installer will run the script: https://github.com/roots/bedrock/blob/1.8.1/composer.json#L55-L57
Which really isn’t much. It’s also not necessary with Trellis as the .env file will be created for you