It is too fast for making prediction monero can challenge bitcoin, although monero's price growing up in my opinion it is fluctuation price only and it will going down again soon. But it is just my prediction too.
Market cap or price are more a measure of speculative betting than actual currency usage. So I wouldn't care too much about market cap. In fact, the too high market cap of bitcoin damaged it more than anything: institutional finance jumping in, regulators jumping in, ... all this without any increase in usage of bitcoin as intermediate asset or "to buy stuff on the internet". MOST of bitcoin's market cap is made up by gamblers/speculators/"investors" which have their stuff on exchanges most of the time ; so just having tokens on an exchange's web page without any block chain would be just as good for them. This has damaged bitcoin more than anything else.