Oh, yeah, about that...

My apologies for not following up in a timely manner. During the move, and all, I completely forgot about the fact that the question still needed an answer.
The Fenris Bike's Primary Attack is performed during it's Move Action, and may strike any model within one inch of the model. The Secondary Attack is performed at the end of the Move (if able to reach base contact with an enemy model), and is, for all intents and purposes, a charge made by the driver, using the vehicle's ST (if the bike moved at least 3"; the driver's ST, otherwise) to calculate Damage.
Intervening models should not be a consideration, as normal charge rules apply with each attack; in other words, the first attack is performed by moving toward the first, closest model, and then may attempt to "ram" another (next closest) model. If any models are, already, engaged in CC, they may be ignored.
Does this clarify it?