weekend event:Double Gold, Scrolls and XP for Vanquishing

"Starting at Noon Pacific (-7 GMT) this Friday, receive double the gold and experience rewards when you successfully vanquish certain areas in Hard Mode. In addition, we've doubled the drop rate of scrolls, and scroll effects will last twice as long as normal. These bonuses last through Sunday at 11:59 PM Pacific (-7 GMT)."

meaning no double reputation points/allegiance faction?

These "Double Gold, Scrolls and XP for Vanquishing" weekend events do award twice the faction or reputation points upon completion of a vanquish. It's never listed in the description but, historically, twice the points has been given.

It might be a bug - seems like someone at Anet got over excited when multiplying values by 2.

They do? So another weekend to get kurz and or lux?

This is probably caused by the rep/faction being calculated directly from the awarded exp value being multiplied with a factor (based on the zone you are in) and not being calculated from the killcount. This in turn has two reasons: prophecies not having any rep and having it calculate it in the end based on the killcount could result in odd bugs. For all prophecies areas, the factor is set to 0, resulting in no rep being gained.
The second reason would be that faction/rep being the same per kill everywhere using the exp/gold calculations; they can't differentiate it properly with the standard vanquish reward calculations for exp/gold (if they changed it, it would be easy to break with bugs). This could be problematic as the different reps/factions have a different value per point: 5 luxon faction per kill is alot less then 5 sunspear rep.

Aspi: Yes, they do. However, do remember the bounty/blessing rewards will not double.

Nice, time to max some things.

OT also Noord-scharwoude pretty close to where I live. Heerhugowaard. Completly irrelevant and unrelated