Responding to 4 years old comments here, but IMO it's safe to assume Sakura, her brother, Syaoran and Meiling are all bisexual. There's no way 'the author didn't have a clue', Card Captor Sakura has actually a lot of gay representation, there's even a non-binary character.
If you get the chance try rewatching the series in Japanese with subtitles, the dubbed version had a lot of the gay stuff censored.