Yes. The purpose of this sort of password convention is to make it more human friendly (easier to remember or dictate), while maintaining security.
Password strength / entropy is all about how long would it take an attacker to brute force. Practically, we think about this in terms of S(p) = number of possible tries / tries per second. This yields how long it would take an adversary to crack your password, in the worst case (that your password was the last possible guess.
The set size of all possible characters varies by system. But, typically, we see set sizes up to about 95 (lower case, upper case and special characters). Let's say everyone knows that bitwarden creates passphrases that are all lower case and have spaces. Passphrases use a word set of (let's say) 170,000.
Your (let's assume) 20 character password has a max number of guess of 95^20 whereas bitwarden has a complexity of 170,000 (choose) 5. However, if the adversary didn't know you used bitwarden, the complexity would look more like 95^40. It's obvious that the more an adversary knows about your password, the faster they can guess it.
You can use a site like security(dot)org to determine how long it would take a computer to crack it (they don't really define what "A computer" is). In either case, either password would take longer than the existence of the universe, by far.
On a side note, I'd love to see a "How secure is my password?" that calculate the cloud compute cost of cracking the password, say in a year. It would be cool to know it would take $5,000,000,000,000,000,000... to crack your password in a year.