How long will it take for me to learn bass?

Hey guys, I was thinking about picking up a bass guitar! I love Bass I love the groove and everything it's just so awesome, it adds epicness to songs. I'm almost level-4 in piano and I play school cello for two years now (not an experienced player) and I can read tabs on guitar and play simple songs like "Smells Like Teen Spirit." However, I suck at tuning my guitar so I can't tune my guitar to play all the songs that I like. I was wondering, on bass do you have to do that or are you on standard the whole time? If I get a bass guitar I'll play it about two-three hours each day, I'll put a lot of time and dedication but how long would it take to learn bass parts to pop rock songs or songs like "She Will Be Loved" by Maroon 5? And how long would it take to learn "Hysteria" by Muse on Bass?