Yes.  As long as it's not associated w/ spraying (backing up to something,
tail quivering, & marking w/ urine), then it just means they're all excited
&/or happy.  One of my cats does the quivering tail a lot ("Oh, hello, I'm
so happy to see you!" sort of deal), & my first cat used to do it when I
opened her favorite kind of food as a treat.

Cathy

--
"Staccato signals of constant information..."
("The Boy in the Bubble")  Paul Simon

We call it "happy tail".

Karen

One of my cats also has this tail quiver. I thought at first it was
based on urine-spraying behavior, but she is a SHE - not known for
spraying, and she's also been spayed, so I dropped this idea. After a
few times, I began to think that this was a form of intense excitement
or pleasure - she used it when I got back home after a few hours away,
she used it when I was offering some tasty treats or food, she used it
when we were involved in a petting/scratching session. Probably the same
thing in your case.

Jim

Most of my cats do it too (including females). There's one male and
one female who do it all the time. Sometimes I'm sitting in front of
the computer and they come to me and quiver their tail against my
legs. I guess it's also a way they ask for attention. One of them (the
male) will insist to the point of climbing on the table and throughing
his body over the mouse. I need to stop what I'm doing and hold him
for a few minutes or he won't let me work.