No, he's too young. He's like 20 but he's not that far away. I'd imagine he starts next year in Mesa maybe south bend but could finish in Mertle Beach. That basically would put his ETA at about 3 years. Basically, I'd picture him similar to Torres this year going into next. Torres was only 18 this year but played almost all year at A ball and got called up to A+ for the playoffs.
With that being said, don't sleep on him. He's got a pretty good tool set and good speed. Given the overall lack of CF depth in the cubs system(especially if Happ who they drafted moves to 2B as he is in instructs) he's really a nice addition for more or less money.
To give you an idea of his tool set Kiley McDaniels of fangraphs gave him a potential grades of
Hit: 50
Game power: 45
Raw power: 50
Speed: 65
Field 55
Arm 55
The best CF in the past draft was apparently Andrew Benintendi who the Sox took at 7. He has the following potential grades
Hit: 50+
Game power: 50+
Raw Power: 55
Speed: 60
Field: 55
Arm: 50+
So basically you're looking at roughly an equivalent top 10 pick by draft standards. MLB.com liked Martinez slightly better based on grades. Giving him 60's on everything but run where he has a 70 grade. McDaniels is usually a bit more conservative than mlb.com but if you translate his scouting rankings into typically game stats you're looking at like .260ish hitter with 15ish HRs and probably 30ish steals and many think he can be pretty decent in CF. Obviously not mike Trout we're talking about here but definitely a decent CF prospect.