2x bonus light is probably the SCR on the driver board. That is usually the issue for locked on controlled lamps. I don't know if the bulb would flash in lamp test if the transistor was locked on though. It may, I am not sure how the lamp test sends power to the lamps. Someone else can probably help but I suspect the SCR at Q46 (2N5060).

The 3000 arrow behaves similarly on my MH so that is probably fine. (you always get 3k for the saucer shot). I don't see that listed in the lamp driver board schematic so it may be a GI lamp.

For bulbs that won't light it is either the socket, the wiring (rare), the connection between the board and the wire, or a problem on the board itself.
If you have a good bulb in there and put it on lamp test and then wiggle the bulb and socket you can usually see if you can get the bulb to light even for a second. If it does your problem is on the socket. If it doesn't light at all I like to jumper that socket to a working and lit controlled socket to see if it then lights. If it does light then your problem is not the socket.
There are fixes to make a socket work again if that is the problem (https://pinside.com/pinball/forum/topic/nics-american-pinball-tour-aka-im-coming-to-fix-your-games/page/14#post-3805597) or you can just replace the socket. I also find that if I am feeling lazy sometimes just adding extra solder to the bulb end itself will make the connection tighter.
If the problem is a connection on the board you should look at the schematics (https://www.ipdb.org/files/4501/Bally_1978_Mata_Hari_Lamp_Driver_Schematic.jpg)and then wiggle that wire at the board. sometimes that will show you that that is the flaky connection.

The problem could also be on the board itself, but start at the socket and work back .

If it is part of the GI circuit as I suspect it will come on with all the General Illumination lamps on the playfield and behind the back glass as those are not controlled by the mpu. They come on as soon as there is power.

What I was describing with the jumper is similar to what you referenced in that post but instead of jumping the suspect socket to a working socket to see if the working socket lights, you are connecting the non working lamp to a working lamp to see if the non working lamp will light up. You are taking the power from a known source and seeing if that lamp socket will work. If it works you know it is not getting power. What you did gets you to the almost the same place, except you don't know if the sockets are working so that is potentially frustrating if you are dealing with both issues at the same time without knowing about it.

If you are looking at the SCRs on the board and you have a multi meter you can test them.