its impossible to say what you will get - are you pleading guilty? unfortunately you have no mitigating factors, and no reasonable reason to be able to keep your driving lisense if you do get 6 points. On the plus side, you will be able to take your driving test again and start again if you do get it revoked.
Bikes can often seem like they are speeding even when they arent - i reckon its some sort of visual trick because they are smaller than cars. Even if he was speeding, it dosent really provide you with mitigation. As for only just being over the line, that dosent either - the user of the carriagewy is entitled to use all the carriageway if they wnt