I haven't found anything recent yet, but this is from WT 15 Dec 1974 and is referred to in the Nov 1983 KM
It doesn't say it is up to the conciences of the elders.
Questions
from Readers ?
What is the view of Jehovah?s witnesses toward attending the wedding of a worldly acquaintance or relative?In the case of minors who contemplate attending, the final decision rests with the parents. Otherwise it is a matter for personal decision, with each Christian being willing to bear his own responsibility. However, there are Scriptural principles and a wide variety of circumstances that should be considered.
The wedding ceremony may be conducted in a religious building and by a clergyman. This would make it quite different from a purely civil ceremony. A true Christian could not conscientiously join or participate in any prayers or religious exercises that he knew to be contrary to Bible teaching. Nor is he interested to see how close he can come to apostate acts without overstepping the line. He is under obligation to heed the Scriptural command: "Do not become unevenly yoked with unbelievers. For what fellowship do righteousness and lawlessness have? . . . Or what portion does a faithful person have with an unbeliever? . . . ?Therefore get out from among them, and separate yourselves,? says Jehovah, ?and quit touching the unclean thing.?"?2 Cor. 6:14-17.
Understandably, one invited to attend a wedding of worldly relatives and acquaintances may at times be faced with quite a problem. For example, the invitation may have been extended to a Christian wife and her unbelieving husband. He may think that both of them should be present for the wedding. Yet she may be troubled about it. She may reason that, if she were to attend a church wedding, the emotional pressure of the circumstances could cause her to do something wrong. On the other hand, she might conclude that, out of regard for her husband?s wishes, she could go with him merely as a respectful observer, but being determined not to share in any religious acts.
Regardless of how a wife might view the matter, it would be to her advantage to explain her position to her husband. If, on the basis of her explanation, he comes to the conclusion that his wife?s presence may possibly give rise to a situation unpleasant to him, he may prefer to go alone. Or, he may still want her to go with him, but as a quiet observer, in which case she will have to decide whether to go.
Something that deserves consideration is the effect that attending a wedding in a religious building might have on fellow believers. Could it injure the conscience of some? Might their resistance to engaging in actual idolatrous acts be weakened by this action of yours? A Bible principle that comes into the picture is: "Make sure of the more important things, so that you may be flawless and not be stumbling others up to the day of Christ."?Phil. 1:10; see also 1 Corinthians 8:9-13.
At times an invitation to a wedding may include being actively involved as a member of the bridal party. What if this required participation in certain religious acts? Manifestly one desiring to be pleasing to God could not share in acts of false religion; the person must act in harmony with his Word. But a Christian could explain just how he feels and point out that in no way does he want to mar the joy of the wedding day by being responsible for what might prove to be an embarrassing situation.
In matters of this nature, Christians must carefully weigh all the factors involved. Under certain circumstances they may conclude that no difficulties would arise if they were to attend as quiet observers. On the other hand, the circumstances may be such that a Christian may reason that likely injury to his conscience or that of others by attending such worldly wedding outweighs the possible benefits of attending. Whatever the situation, the Christian should make sure that his decision will not interfere with his preserving a good conscience before God and men.
