jamplay gave me a temporary login, and there wasn't enough bass stuff there imo. i found it disappointing. i suspect there's a lot more there for guitar players.
i never joined scott's but i have checked out his free lessons. i think he's a good teacher who gives a lot of detail, and if that's what you're looking for, his site has a lot of features. if i were looking for online lessons, this would be where i'd go. scott's bass lessons has a 14-day free trial you can check out to see if you like it, but if it's like other free trials they may put a hold against your card. to find out if that's the case, you could email them - they've been good at responding to my emails.
i'm not familiar with bassbuzz, seems mostly focused on beginners to intermediate judging by their site, but that's not a bad thing if it's what you're looking for.
also if you're looking to learn by playing songs, paul wolfe has a number of online classes and tutorials
How To Play Bass
and you can check out his bass lessons on youtube - he has a lot of older ones online. his method is to explain what strings and frets to play to play complete songs. not a lot of theory that i'm aware of, but he has at least one beginner course that i believes goes from easiest beginner songs and gets a little more complex with each song. he's got other stuff, too.