Mario vs Tink is a spamfest obstacle course to put it simply. Tink has no reason to approach (without a bomb) unless he's landed a hit confirm for his basic hit and run combos. The thing about his combos is that he hits hard. So, you have to make sure you're paying attention and not trying to force yourself through his projectiles when you have no real leverage. Normally, Tink suffers the same issue in the projectile game as Mario (having someone under him), but with a bomb in his hand, things change up since you don't want to trade or get baited into one. You can cape his projectiles, but cape can set you up to get smacked if not used from further away. For the most part though, cape doesn't really sway this matchup in anyone's favor.
I don't know the specifics, but you can hit a bomb without making it explode, and that'll help you when pressuring Tink, but for the most part, make sure you dodge, cancel out, and shield his projectiles. Tink is fast as hell, so he can run away most of the game. Even if you get close to him, the other half of the battle is landing a solid hit confirm to start anything. Tink's grab will blow you up, and you really don't want to eat Dthrow > UpB. His backside is covered fairly well cause of Bair (I know this from Brawl), and if I'm not mistaken, he can probably link multiple Bair's for serious damage.
Zair is also another issue that can come up against us. A Tink with some stage to work with, can keep us away with Zair, and it has easy hit confirms if you're just running into it. You want to make sure that while you're trying to get in, you push him back so that he doesn't have room to work with and set up his crap. Once he's offstage, edgeguard the crap outta him. Bomb jump will make him get back, but he can't focus on his opponent as much while doing it.
Overall, I call it even. You're playing his game until you can push him towards the edge. Once you get in, you can go to town with him, but you'll be playing the game again after you finish your combo/kill. As for stages, I didn't necessarily like having to play on completely flat stages or stages with tons of platforms. Small is cool for us (GHZ & FoD), and even ones with a little space, but with minimal platforms (PS2, PS1, & SV).
I have one match where I played a competent Tink for my first time in PM, but most of my experience is from the camping Tinks gave me in Brawl. Being able to handle spam is the crucial point.
http://www.youtube.com/watch?v=8IDvOx6bZ_s
Shoutouts to chokin' the last kill, and gettin' bopped by Luigi in game 2. >_<