Bad news first. This place is all cactus and thorn trees. Their spines blow everywhere, including onto the roadways. I run Slime and Tuffy liners in my MTB tires and still get flats regularly. If you don't ride offroad and stay off the shoulder, they're not so much of a problem.
Theres not much traffic where Habitat is (usually) and the roads are comparatively decent. You might find the scenery interesting; it depends on what you're looking for. On the weekend the local roadies do the loop from town out to Westpunt and back. And theres MTB trails out there, too.
This map roughly covers the kind of range youre talking about. Habitat is near the middle at the bottom.
It isnt an especially hilly area but Habitat is separated from the rest of the island by a pretty good ridge. Its a fair pitch up to the guard shack and a fast descent into Willibrordus on the other side.
The outskirts of Willemstad are 16KM by road to the southeast. I'd recommend you not go any farther in that direction than Daniel. Past there, you'd be on what passes for a high speed thoroughfare all the way to Willemstad.
To the northwest, different story. It gets more rural and more sparsely populated as you go. Frequent beaches, lots of 'local color'. My guesstimate is that it's a bit less than 35KM from Habitat to Westpunt via Weg Naar Santa Crus.
Is it bike-able? Yeah, I think so. Then again, I MTB'd in Iraq.