This is part of what you cited.
Thus, when an affidavit is submitted by someone who can be directed to appear in person at trial only through such a subpoena, a local address at which the affiant is personally present for pretrial service is necessary — unless, of course, the person fits within a recognized exception to the personal service rule, in which case an address that permits proper service upon an appropriate representative will suffice. When an affiant also can be summoned to appear at trial through a notice to attend served on an attorney (§ 1987, subd. (b)), however, either a local address where the affiant will be personally present for service of a subpoena or a local address of the attorney will suffice.”
In the above, the court states that the only way service is permitted on a representative is if the witness “fits within a recognized exception to the personal service rule.” Here are the exceptions the court listed.
There are a few established exceptions to the general requirement that, in order for a party to compel a person to appear at a civil trial, that person must be personally served with a subpoena. When the subpoenaed person is a minor, the subpoena must be served on a parent, guardian, or other person identified by statute.
Likewise, certain public employees (such as police officers and firefighters) need not be personally served with subpoenas to secure their appearance at trial, at least when their testimony would concern matters associated with their professional duties. In these situations, effective service of a trial subpoena can occur by personal service or by "delivering two copies to [the prospective witness's] immediate superior at the public entity by which he or she is employed or an agent designated by that immediate superior to receive that service." (Gov. Code, § 68097.1, subd. (a); see also id., §§ 68097.1, subd. (b), 68097.3.)
Furthermore, no subpoena at all is required for the production at a civil trial of a party, or "a person for whose immediate benefit an action or proceeding is prosecuted or defended or . . . anyone who is an officer, director, or managing agent of any such party or person." (§ 1987, subd. (b).) Such a party or person may be summoned to appear at trial through service "upon the attorney of that party or person" of "written notice requesting the witness to attend . . . a trial," with service to occur no less than "10 days before the time required for attendance unless the court prescribes a shorter time."
The court stated that Portfolio’s witness did not fit those exceptions.
Service on the attorney only applies under certain exceptions. Portfolios witness did not fit the exceptions. Here’s what the court said.
”Effective use of a notice to attend is limited to situations in which the witness whose attendance is desired is a party or someone closely affiliated with a party, as specified by statute. (§ 1987, subd. (b).) Because Eyre is neither, his appearance as a witness at trial could be secured only by a subpoena, which by law must be personally served, absent an exception — none of which applies here.”