It depends on configuration of authentication system of the site. If it was setup to log any attempts - than yes, it is now in the log (text file or database) in plain text. It could look like that:
12-Feb-2014 12:00:00 AM: Unsuccessful login attempt user (YOUR_PASSWORD_HERE) from (YOUR_IP_HERE);
It is still true that password will not be accessible for regular users. Only for those who have access to log files.
What consequences it implies?
- If server would be compromised - than hacker theoretically will have your plain text password.
- Site's admin could routinely go thru the log files and accidentally find your password. He can than find what IP address this record came from and thus he can theoretically find what is your username and e-mail (because he has access to the database).
So, if you have same email/username/password on other resources - than change it immediately. Because there are chances that your password will be found. Logs can remain on servers for years.