Speaking as someone who used to work at a company that several bootcamps had pitched for recruitment purposes, and having met several grads from bootcamps, I would say that these bootcamps are most certainly not for you. They are almost all universally geared towards beginners. In that sense these bootcamps do add a lot of value. It is really hard to teach yourself to code if you lack any foundation in coding, let alone teaching yourself X or Y technologies.

There is really nothing these bootcamps can offer you except for a boost in your motivation (such a boost is not worth $12-17k+). To give you a sense of what I mean, Dev Bootcmap, for example, spends half of its time on teaching their students Ruby and programming fundamentals, which makes sense if you've never/barely coded before, but does not make sense for someone with experience who can teach him/herself Ruby and most of its advanced concepts over a (focused) weekend. Even Hack Reactor, which bills itself as being more intensive and faster-paced, spends a lot of time on basic language/CS fundamentals.

These programs don't really improve your job prospects beyond the improvements that are due to a beginner learning new concepts, nor do they really provide any sort of networking opportunities beyond the kind of networking you can achieve by hanging out at engineering meetups once a week - the average wage at these programs is almost universally in the $85k area, which sounds like a lot but is essentially entry level for the SF area.

The same applies to most online course material out there, which is geared towards beginners.